Nov 3, 2024
46 minute read

How to Open Big CSV Files – an Ultimate Guide


TLDR; Opening large CSV files can be tough due to software and hardware limitations, but there are practical tools and strategies to make it easier. This guide covers a range of solutions, from basic to advanced: starting with spreadsheet tools like Excel with Power Query and LibreOffice Calc, which handle larger datasets better than typical spreadsheets. We then explore text editors like EmEditor and UltraEdit, optimized for quickly loading and editing big files. For more advanced data work, we move on to databases like SQLite, MySQL, and PostgreSQL which allow efficient querying. Then we move on to explore command-line tools like CSVkit and xsv for fast, efficient CSV file handling. After that, we touch on programming languages like Python and R that offer powerful processing capabilities. By understanding each tool’s strengths and limitations, you can find the best solution to open, process, and analyze your large CSV files effectively.

Ever tried opening a large CSV file and watched your software crash or your computer freeze? Handling big CSV files can be tough due to software limitations, hardware constraints, and sheer data volume. For example, Microsoft Excel, which many users initially turn to, has row and column limits (1,048,576 rows by 16,384 columns in Excel), making it unsuitable for larger datasets. In this comprehensive guide, we'll show you effective solutions to open and work with big CSV files.

Before diving into the tools and techniques, it's worth noting that while CSV is a common format, other formats like TSV (Tab-Separated Values) and Excel’s own XLS or XLSX formats are often used. Many of the tools we’ll discuss are not limited to CSV files and can handle these formats too. You can easily export an XLS or XLSX file to CSV and use the methods we’ll outline to work with these large files efficiently.

We've organized the methods from the simplest tools to the most advanced and capable approaches, allowing you to choose the solution that best fits your needs and technical expertise. We'll explore various methods — categorized into software tools, programming approaches, and best practices — to handle large CSV (and similar) files efficiently.

Here we brought a detailed overview of the selected tools for handling large CSV files:

CategoryToolLicensePlatformMax Capacity (File Size/ Count)Free VersionTechnical ExpertiseSystem Resource UsagePerformanceKey FeaturesLimitations
Excel AlternativesLibreOffice CalcOpen-sourceWindows, macOS, Linux~1M+ rowsYes (Open-source)LowModerate RAM usage, better than Excel for large filesPerformance decreases with very large datasetsFree alternative to Excel, handles slightly larger filesSlows with very large files, lacks Power Query equivalent
Power QueryPaidWindows, macOSNo specific row limit, but subject to available system resources (memory, CPU).No (Included in paid Excel, but it’s available free in Power BI Desktop)LowHigh RAM usage, proportional to file sizeHandles medium to large datasets, but performance decreases significantly with larger filesFamiliar interface, advanced data import, handles larger files than Excel without Power Querymemory-intensive for large datasets
Online CSV ToolsCSV ExplorerFreeWeb5 Million rowsYesLowLight resource usageEfficient for moderate files up to 5 GB, but slows with very large filesSimple file upload, fast filtering, sorting, no installation neededInternet required, lacks advanced data manipulation features
Zoho SheetFreeWebNot specified explicitlyYesLowLight resource usageSlower with huge files, and limited advanced data manipulation.Cloud-based, Excel compatibility, real-time collaboration.Slower with very large files, lacks advanced data manipulation features.
Google SheetsFreeWeb10M cellsYesLowDepends on browserSlower with large files due to browser and internet dependencyCloud-based, easy collaboration, no need to installMax 10M cells, slower with large files due to internet latency
Text EditorsEmEditorPaid license with Free trialWindows16 TBNoLowLow to moderate RAM usageVery fast even with extremely large filesVery fast with large files, CSV mode for tabular viewPaid license
UltraEditPaidWindows, macOS, LinuxMulti-GBNoLowHigh RAM usage for very large filesHandles multi-GB files well but slows with very large datasetsSome CSV editing features like column mode editingPaid software, resource intensive for extremely large files
Large Text File ViewerFreeWindowsMulti-GB filesYesLowLow resource usage, does not load entire file into memoryFast viewing of large files without high memory usageQuick viewing and searching of large CSV and text filesNo CSV specific features and load CSV as text, Read-only, cannot edit or manipulate data
Advanced Desktop Applications for CSVModern CSVPaidWindows, macOS, LinuxMulti-GBNo (Free trial)Low to MediumEfficient RAM usage, optimized for large filesPerforms well with multi-GB datasetsAdvanced CSV editing, fast performance with large filesPaid license required for continued use
OpenRefineOpen-sourceWindows, macOS, LinuxMedium to large filesYesMediumModerate RAM usage, depending on data sizePerforms well with data cleaning tasks, not optimized for extremely large datasetsPowerful data cleaning and transformation, open-sourceSteeper learning curve for beginners
Tad ViewerFreeWindows, macOS, LinuxMulti-GBYesLowLow resource usage, handles large files efficientlyVery fast for viewing large filesSimple CSV viewer, lightweight, fast with large filesRead-only, lacks editing features
Command-Line ToolsCSVkitOpen-sourceWindows, macOS, LinuxMedium to large filesYes (Open-source)High (CLI skills)Low resource usage, efficient with large filesPerforms well with medium to large files, but limited for extremely large filesSuite of CSV utilities, SQL-like querying, powerful for data filtering and manipulationNot optimized for extremely large files
AWK, sed, grepOpen-sourceUnix/Linux, macOS, Windows (with compatibility layers)Very large filesYes (Open-source)High (CLI and scripting skills)Low resource usage, efficient line-by-line processingHigh performance due to streaming capabilityPowerful text processing, pattern matching, substitution, stream editingNot optimized for complex CSV parsing, advanced scripting required for complex tasks
xsvOpen-sourceWindows, macOS, LinuxMulti-GBYes (Open-source)High (CLI skills)Low resource usage, very efficient for large filesPerforms well with large datasets due to streaming capabilityHigh-speed CSV processing, supports streaming data, lightweightLimited advanced features, less user-friendly than GUI tools
DatabasesSQLiteOpen-sourceWindows, macOS, LinuxLarge datasetsYes (Open-source)Medium (SQL knowledge)Low resource usage, handles large datasets efficientlySolid performance with large datasets in read-heavy operationsLightweight, file-based database, easy setup, supports SQL queryingLimited concurrency, not ideal for write-heavy operations
MySQLOpen-sourceWindows, macOS, LinuxVery large datasets (TBs)Yes (Open-source)High (Database admin skills)Requires more RAM/CPU for large queriesSolid performance for bulk data imports, scalableScalable, fast bulk data imports, SQL queryingRequires setup and server management, more complex for beginners
PostgreSQLOpen-sourceWindows, macOS, LinuxVery large datasets (TBs)Yes (Open-source)High (Database admin skills)High resource usage for complex queriesSolid performance on massive datasets, fast bulk importsFast imports, flexible SQL querying, handles huge datasets efficientlyRequires setup and server management, steep learning curve
Programming LanguagesPythonOpen-sourceWindows, macOS, LinuxLarger-than-memoryYes (Open-source)High (Programming skills)High memory usage for Pandas, better with DaskEfficient with smaller datasets, Dask scales for large datasetsExtremely flexible, parallel computing with Dask, supports chunked file reading for large datasetsRequires coding knowledge, memory issues with large datasets unless using optimized libraries like Dask
ROpen-sourceWindows, macOS, LinuxMulti-GBYes (Open-source)High (Programming skills)Moderate RAM usage, efficient for large datasetsHigh-performance for large datasetsHigh-performance data manipulation, memory efficient with large datasetsLearning curve, memory limitations for datasets larger than available RAM unless optimized

Handling large CSV files is tricky. They often grow quickly when exporting entire databases or detailed records like logs or transactions. The more comprehensive the dataset, the bigger the file, and that’s when the real challenges start to surface.

Avoiding these issues and obstacles requires the right tools and strategies, but understanding the common pitfalls is the first step to ensuring the smooth handling of large CSV files.

  • Software Limitations: Tools like Excel have a hard row limit — Excel’s cap is 1,048,576 rows — and attempting to open files exceeding this limit can cause the software to become unresponsive, or only load a portion of the data without warning.
  • Hardware Constraints: Large files put a heavy load on your system’s RAM and CPU, which can slow everything down or even cause your computer to freeze or crash.
  • Data Integrity Risks: When software crashes mid-process, you risk data loss, and some programs might even truncate the file without warning.

When dealing with complex columns, such as JSON data within a CSV export, several common parsing issues can arise:

  • Incorrect Delimiter Detection: Sometimes, the program gets the delimiter wrong, leading to data misinterpretation or corruption, for example when there are quotes in cell values.
  • Multiline Records: Fields that contain newlines can throw off parsers, leading to errors in reading the file.
  • Encoding Problems: Differences in character encoding can cause import issues, especially when handling data from diverse sources.

Now that we've explored why CSV files could get so large and the challenges they present when you need to open and work them, let's focus on how to choose the right tools to handle them effectively.

  • Performance and Speed: Handling large files efficiently without excessive resource consumption.
  • Ease of Use: User-friendly interfaces and minimal learning curves.
  • Cost: Availability of free or open source solutions versus paid solutions.
  • Platform Availability: Windows, macOS, Linux platforms or Web-based.
  • Features: Advanced data manipulation, filtering, and analysis capabilities.
  • Scalability: Capable of efficiently opening and processing CSV files ranging from gigabytes to terabytes.

If you want to try out the methods mentioned in this guide for handling large CSV files, here are some publicly available datasets to practice with:

In the following, we brought together a categorized list of the best tools — both code-based and non-code-based — to help you work with large CSV files, regardless of your technical expertise.

In this section, we detail the top spreadsheet-based methods for managing large CSV files effectively.

LibreOffice Calc is a free, open-source alternative to Excel that can handle large files more efficiently.

Step-by-Step Guide:

  1. Download: Get LibreOffice from its official website and launch it on your computer.

  2. Import CSV: Go to 'File > Open', select your CSV file, and click 'Open'. LibreOffice Calc 'Import Data' dialog with 'Only Create Connection' and 'Add this data to the Data Model' selected.

  3. Set Import Options: In the Text Import dialog, choose the appropriate Character Set (e.g., UTF-8), select the delimiter used in your file (for example, a comma for CSV or a tab for TSV), and adjust other settings as needed. LibreOffice Calc Text Import dialog with character set, separator options (Tab, Comma), and CSV data preview.

  4. Edit Data: Your data is now editable in Calc. CSV file loaded in LibreOffice Calc showing a table with columns for ID, name, and email addresses.

    The CSV files used in the tools and guides were generated using the Faker library.

To improve performance, you can adjust memory settings under 'Tools > Options > LibreOffice > Memory'. While LibreOffice Calc handles up to a million rows — equal or a little bit more than Excel — it struggles with multi-gigabyte files and can become unresponsive, unlike Excel's Power Query, which we’re going to explore in the next section.

Using Power Query, you can import large CSV files more efficiently than Excel itself. It bypasses the 1 million row limit by loading data into the Data Model, making it faster and more capable.

Step-by-Step Guide:

  1. Getting Started: Get Excel from its official website and launch it on your computer.

  2. Access Power Query: Navigate to the 'Data' tab on the ribbon.

  3. Import Data: Click on 'Get Data > From File > From Text/CSV'. Excel screenshot with 'From Text/CSV' option highlighted in the Data tab under the 'Get Data' menu.

  4. Select Your CSV File: Browse to your CSV file, select it, and click 'Import'. After selecting your file, you’ll see the below window: Power Query preview of a CSV file showing the first 20 rows with columns for id, name, and email.

  5. Preview and Transform Data: Excel will load a preview of the data. Click 'Transform Data' to open the Power Query Editor. Power Query Editor displaying a loaded CSV file with applied steps and column headers for id, name, and email.

  6. Optimize Import Settings By Disabling Data Type Detection:

    • In the Power Query Editor, go to 'File > Options and Settings > Query Options'. Excel Power Query Editor showing the 'Options and Settings' menu for adjusting query and data source settings for large CSV file import.
    • Under 'Global > Data Load', uncheck 'Detect column types and headers for unstructured sources'. Excel Query Options with 'Automatically detect column types' unchecked under Data Load settings.
  7. Load to Data Model:

    • Click on 'Close & Load To...' in the Home tab. Power Query Editor displaying ‘close and load to…’ option, with id, name, email columns, and 'Source' as the applied step in query settings.
    • In the import dialog, select 'Only Create Connection' and check 'Add this data to the Data Model'. Excel 'Import Data' dialog with 'Only Create Connection' and 'Add this data to the Data Model' selected.
  8. Work with Your Data: You can use PivotTables or Power Pivot to analyze data from the Data Model without loading it into the worksheet grid.

Remember to save your work frequently, as large data operations can still cause Excel to crash. Even with Power Query, Excel relies heavily on RAM, so handling multi-million-row datasets can lead to slowdowns, freezing, or crashes — especially during complex tasks.

While spreadsheet software applications are user-friendly, they struggle with large datasets, often leading to slowdowns or crashes. For handling bigger files more efficiently, let's explore more advanced tools designed for optimal performance with larger CSV data.

Online tools offer a simple, convenient way to handle medium to large CSV files without installing extra software on your local machine. They're great for quick data checks, collaboration, and working across devices seamlessly.

CSV Explorer is a user-friendly online tool designed to easily upload and manage large CSV files. It offers key features like filtering, sorting, and basic data visualization, allowing you to analyze and explore datasets all in the browser.

Step-by-Step Guide:

  1. Getting Started: Go to csvexplorer.com in your browser and sign up to start using the tool.

  2. Upload Your CSV File:

    • Click on the 'Import Data' button. CSV Explorer dashboard displaying dataset options, an "Import Data" button, and tutorial sections for managing CSV files.
    • Click on the 'Choose File' option and select your CSV file from your computer, Google Drive, Box, or URL. CSV Explorer file upload dialog with options to drag and drop or select a file from your computer, Google Drive, Box, or URL.
  3. Open imported CSV file: In the list shown below 'Datasets' click to open and view your imported CSV file: CSV Explorer displays a dataset named "Movies" with 58,098 rows and a tutorial section for managing and analyzing CSV files.

  4. Work with your CSV file: After opening CSV data, the sidebar options show that tasks like 'Search', 'Sort', 'Create Histogram', 'Download', and 'Split and Download' can be done. CSV Explorer displays a dataset with 58,098 rows, showcasing movie titles, genres, and release years in a searchable and filterable table.

However, CSV Explorer does have its weaknesses too, such as a 5 Million rows cap and fewer advanced data manipulation features compared to desktop tools. While it's great for quick data checks and basic tasks, more complex analysis might require additional solutions.

Zoho Sheet is a versatile online tool that lets you easily manage large CSV files, with key features like real-time collaboration, cloud storage, and seamless Excel compatibility. Its data analysis tools, including formulas and pivot tables, make it ideal for team projects and basic data processing.

Step-by-Step Guide:

  1. Getting Started: Go to the Zoho Sheet website in your browser and sign up to start using the tool.

  2. Create a New Spreadsheet: Click on 'New Spreadsheet' or 'Upload' to import your CSV file. Zoho Sheet dashboard showing options to create a new spreadsheet or upload existing files for cloud-based management and collaboration.

  3. Upload Your CSV File: In the 'Upload' dialog, select your CSV file, then choose the appropriate settings for delimiters and other settings: Zoho Sheet web app showing a CSV file upload dialog, with options to set delimiter, date format, and a preview of the CSV data.

  4. View and Edit Data: Your CSV data will be displayed in spreadsheet format, then you can use standard spreadsheet functions to analyze your data. Zoho Sheet displaying a large dataset with movie titles, genres, and release years, showcasing the intuitive interface for organizing and analyzing CSV data.

  5. Collaborate with Others: Share the spreadsheet with team members for real-time collaboration.

  6. Save and Export: Zoho Sheet automatically saves your work in the cloud. And, you can Export your spreadsheet in various formats if needed.

However, Zoho Sheet can slow down when handling very large files and lacks some advanced features found in desktop applications. For heavy data tasks, you might need more robust tools to avoid performance issues.

Google Sheets is an online spreadsheet tool that can handle up to 10 million cells.

Step-by-Step Guide:

  1. Getting Started: Go to Google Sheets and sign in with your Google account.

  2. Import the CSV File: Click on 'Blank' to create a new spreadsheet, then go to 'File > Import'. Google Sheets with the 'File' menu open, showing options like 'Import,' 'Make a copy,' and 'Share' on a blank spreadsheet.

  3. Upload Your File: In the Import file window, click on the 'Upload' tab, Drag and drop your CSV file, or click 'Select a file from your device'. Google Sheets with the 'File' menu open, showing options like 'Import,' 'Make a copy,' and 'Share' on a blank spreadsheet.

  4. Configure Import Settings: Choose 'Replace spreadsheet' to overwrite the current sheet, and select the appropriate separator type (Comma for CSV), then Click 'Import Data'. Google Sheets import dialog for CSV file with options to replace spreadsheet and select separator type.

Google Sheets allows up to 10 million cells, but it struggles with large datasets in practice. Cloud-based processing can cause delays in loading and editing, and browser limitations often lead to inconsistent performance or timeouts when working with big files.

However, online tools are accessible but require a stable internet connection to function and are constrained by internet bandwidth and browser capabilities. Now, let's proceed with some competent offline options to cover this limitation and much more.

In the following sections — III. Text Editors and IV. Desktop Applications — we provide step-by-step guides using the Windows versions of these applications. But keep in mind that in most cases, Mac and Linux versions are also available for the tool. You can check the overview table at the beginning of the post to see availability for your platform or visit the official site of each application.

EmEditor is a fast text editor capable of opening up to 16 TB file sizes. Combining this capability with its CSV mode you’ll have a great choice for opening large CSV files. EmEditor allows users to seamlessly switch between different delimiter formats like commas or tabs, freeze headers for easy navigation, and manage columns with ease. Advanced features such as creating pivot tables, joining data, and manipulating columns further enhance its capabilities, making EmEditor a powerful tool for both basic editing and more complex CSV file management.

Step-by-Step Guide:

  1. Getting Started: Get EmEditor from its official website and launch it on your computer.

  2. Open Your Large CSV File: Launch EmEditor. Go to 'File > Open' or drag and drop your CSV file into EmEditor. EmEditor CSV mode activated with 1 comma-separated option, showing column-based view for large CSV files, enhancing readability and editing.

  3. Choose a Delimiter: After loading your file, head to the 'CSV' menu and select the appropriate delimiter (e.g., comma, tab) to properly recognize and display your file in a structured CSV format rather than plain text. -EmEditor displays syntax errors for inconsistent CSV columns while working with large datasets, highlighting its CSV validation feature.

EmEditor handles large CSV files efficiently, and while advanced features like the Large File Controller are available in the paid version, it offers a 30-day free trial that provides robust capabilities for basic CSV management.

UltraEdit is great for handling large CSV files, offering features like column editing, automatic width adjustments, and support for delimited data. It efficiently manages multi-gigabyte files while ensuring proper structure during edits, making it a solid choice for working with large datasets.

Step-by-Step Guide:

  1. Getting Started: Get UltraEdit from its official website and launch it on your computer.
  2. Open Your Large CSV File: Launch UltraEdit then click 'File > Open', or drag and drop your large CSV file into the editor.
    • Disable Temporary Files: When opening a file larger than 50 MB in UltraEdit, a warning dialog appears, prompting you to disable temporary files for better performance when handling large files.

      UltraEdit warning dialog about temporary file handling when opening a large CSV file, offering options to improve performance for big data files.

  3. UltraEdit CSV convert option: This option lets you quickly transform the character-separated text into fixed-width fields, ideal for managing large CSV files. UltraEdit displays a CSV convert feature in action, converting character-separated text into a structured CSV format for better data management.

UltraEdit provides essential CSV handling features, such as column editing and basic data sorting. However, it lacks advanced capabilities like multi-level sorting or data merging, making it more suited as a general-purpose text editor rather than a specialized tool for complex CSV processing.

Large Text File Viewer is built to open massive CSV files quickly without consuming too much memory. It's perfect for viewing and searching large datasets with fair performance.

Step-by-Step Guide:

  1. Getting Started: Download the Large Text File Viewer and install the application following the on-screen instructions.
  2. Open and Navigate a Large CSV File:
    • Click on the top left three-dot menu, then select 'App Command' to display the bottom toolbar.
    • Use the 'Open File' button in the bottom right to select and open your large CSV file.
    • The toolbar also offers additional tools for working with CSV files, such as navigating, sorting, and searching data. Large Text File Viewer window opened with CSV file, click the 3-dot menu for App Command, tools for working with CSV in the bottom toolbar.

Large Text File Viewer is a read-only tool, so you can’t edit or manipulate data. For users who need more than just viewing capabilities, this tool falls short.

However, Text Editors aren't designed for deep data processing tasks. If you need features like complex sorting, joining, or data analysis, these tools may not be sufficient and might require switching to more specialized software, which we will explore in the following sections.

Advanced desktop applications for CSV files offer quick access, filtering, and sorting for multi-gigabyte datasets without system slowdowns. They provide powerful, offline solutions that go beyond traditional spreadsheet tools, offering users refined data manipulation and efficient viewing.

Modern CSV is a high-performance CSV editor for Windows which is optimized for handling large files. It offers powerful data manipulation features such as multi-cell editing, sorting, filtering, and batch editing, which makes it a solid choice for users who need both speed and advanced functionality.

Step-by-Step Guide:

  1. Download and Install: Visit the Modern CSV download page and get the version suitable for your operating system.
  2. Open Your CSV File: Launch the application and either drag and drop your file or use 'File > Open' to load your dataset. Modern CSV displaying a large CSV file with over 22 million rows, showcasing efficient viewing and navigation of big data spreadsheets.
  3. Navigate and Edit Data: Utilize features like search, filter, sort, and batch editing.
  4. Data Manipulation:
    • Filtering: Click on 'Data > Filter Rows' to filter data based on specific criteria.
    • Sorting: Click on column headers to sort data ascending or descending.

However, the free version of 'Modern CSV' lacks features like filtering, data joining, and advanced editing, which are available only in the paid version.

OpenRefine is a robust, open-source desktop tool designed for cleaning, transforming, and enriching large, messy datasets. It excels in handling complex data preparation tasks by offering powerful features like Filters, and GREL, for deep data transformations and consistency checks. Users can explore, clean, and filter their datasets based on specific criteria, and integrate external sources like Wikidata to augment the data.

Step-by-Step Guide:

  1. Get Started: Get OpenRefine from its official website and launch it on your computer.

  2. Start the application: Double-click 'openrefine.exe' on Windows or run the script on Mac/Linux, then your default web browser will open the OpenRefine interface.

  3. Create a New Project:

    • Click on 'Create Project'.
    • Under 'Get data from', choose 'This Computer'.
    • Click 'Choose Files' and select your CSV file.
    • Click 'Next' to load your local CSV file and view it in OpenRefine's grid. OpenRefine interface showing the 'Create Project' screen for importing large CSV, TSV, Excel, and JSON files for data cleaning.
  4. Explore and Clean Your Data:

    • Adjust parsing options if necessary in the bottom options panel, for example, the character encoding, and separator character.
    • Use filters and other options to explore data.
    • Perform transformations using built-in functions or GREL OpenRefine interface displaying a preview of a CSV file being processed, with parsed column headers and delimiter options.

OpenRefine is a powerful tool for cleaning, transforming, and working with messy CSV data, but its learning curve and lack of real-time collaboration features, for example, can be a drawback for users seeking straightforward CSV management. However, for users who need robust local data cleaning capabilities, OpenRefine remains a proper pick.

Tad Viewer is a lightweight, free desktop application designed to view and filter large CSV files efficiently. Unlike more complex tools, Tad Viewer focuses on rapid display and filtering without the need to load entire datasets into memory, making it ideal for users who need quick access to large files without system slowdown.

However, it is a read-only tool, so if you need to edit or manipulate your data, you’ll need to use a more feature-rich tool. For basic analysis and lightweight filtering, Tad Viewer is a strong, no-cost option for handling large datasets efficiently.

Step-by-Step Guide:

  1. Download and Install: Head to the Tad Viewer website and download the appropriate version for your operating system (Windows, Mac, or Linux).
  2. Open Your CSV File: Launch Tad Viewer, click 'File > Open', or simply drag and drop your CSV file into the interface for quick access.
  3. Filter and Sort Data:
    • Use the interface to filter rows and columns based on your criteria without requiring a full data load.
    • Sort and organize data by clicking on the column headers, allowing for easy exploration.
    • Utilize the bottom-left tools, such as 'Pivot', to perform aggregations and organize data hierarchically for deeper insights. Tad Viewer interface showing a large CSV file loaded for quick filtering and sorting, highlighting its intuitive data viewing capabilities.

Despite their strengths, these qualified desktop tools have limits. Some are paid or offer restricted free versions, and some lack advanced processing or editing features. For deeper analysis or collaboration, more specialized software may be needed.

Command-line tools offer an efficient and flexible way to handle large CSV files. They process datasets too big for standard apps while using minimal memory, making them ideal for automation and adequate manipulation. Below we brought you three of the best command-line options for handling massive CSV files.

CSVkit is a powerful suite of command-line tools built using Python for working efficiently with CSV files. CSVkit offers an array of utilities to view, convert, filter, and analyze CSV data directly from the terminal. It is a Python-based tool, so you need to have Python installed before working with it. CSVkit offers versatile utilities such as csvcut for column selection, csvgrep for row filtering, csvsort for sorting, and csvstat for summary statistics. It excels in data conversion to formats like JSON and Excel, supports schema extraction by detecting column data types, and enables efficient data manipulation through SQL-like queries using csvsql.

Step-by-Step Guide:

  1. Install CSVkit:

    pip install csvkit
    
  2. Usage Examples:

    • View CSV Metadata: Get statistical summaries of your CSV:

      csvstat large.csv
      
    • Filter Rows: Extract rows where a column matches a specific value:

      csvgrep -c "column_name" -m "value" large.csv > filtered.csv
      
    • Select Columns: Extract specific columns:

      csvcut -c "column1","column3" large.csv > selected_columns.csv
      
    • Convert CSV to JSON: Convert your file to JSON:

      csvjson large.csv > data.json
      
    • Query CSV with SQL: Use SQL queries to manipulate CSV:

      csvsql --query "SELECT column1, SUM(column2) FROM input GROUP BY column1" large.csv
      

CSVkit includes commands that can process data without loading the entire file into memory, such as csvcut and csvgrep. However, while it handles large files efficiently, certain operations may still require substantial memory, making it less practical for extremely large datasets.

The classic Unix tools — AWK, sed, and grep — are essential for text processing and are widely used for large CSV files as well. These lightweight utilities enable flexible pattern matching, text substitution, and extraction without loading the entire file into memory. AWK, sed, and grep are lightweight tools pre-installed on most Unix/Linux systems, requiring no installation. They excel at stream processing by handling data line by line, which avoids high memory usage. Their powerful filtering capabilities allow for flexible pattern matching to extract or modify specific rows or fields directly from the command line.

Usage Examples:

  • Filter Rows with grep: Find lines containing a specific value:

    grep "search_value" large.csv > filtered.csv
    
  • Process Fields with AWK: Perform operations on specific columns:

    awk -F',' '$3 > 100 { print $1, $2 }' large.csv > output.txt
    
  • Edit Text with sed: Replace specific text patterns:

    sed 's/old_value/new_value/g' large.csv > modified.csv
    

While AWK, sed, and grep can handle basic tasks like filtering and replacing text efficiently, handling CSV-specific issues such as quoted fields or embedded commas can be complex and may require advanced scripting expertise.

xsv is a lightning-fast command-line tool written in Rust, optimized for high-performance processing of large CSV files. It efficiently handles massive datasets by processing data in streams, rather than loading everything into memory, making it a popular choice for users working with very large files. xsv offers high performance with minimal memory usage by streaming data, enabling efficient handling of large files. It supports indexing for faster querying and filtering, and includes versatile commands like sampling, frequency counts, and joins.

Step-by-Step Guide:

  1. Install Cargo: If you don’t have Cargo (Rust’s package manager) installed, you can install it by following the instructions on the official Rust website or run this in your terminal, this will install the Rust toolchain, including Cargo.

    curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
    
  2. Install xsv: Once you have Cargo installed, you can install xsv using the following command:

    cargo install xsv
    

    Alternatively, you can download a binary from the releases page if you prefer not to install Rust and Cargo.

  3. View CSV Headers: Display column headers:

    xsv headers large.csv
    
  4. Sample Rows: Extract a random sample of rows:

    xsv sample 100 large.csv > sample.csv
    
  5. Select Columns: Extract specific columns:

    xsv select column1,column3 large.csv > selected_columns.csv
    
  6. Sort Data: Sort the file based on a specific column:

    xsv sort -s column2 large.csv > sorted.csv
    
  7. Join CSV Files: Perform a join operation between two CSV files:

    xsv join column_id file1.csv column_id file2.csv > joined.csv
    

xsv is very fast and memory-efficient, but its scope is limited to common CSV operations. For complex transformations or multi-level joins, more sophisticated tools may be needed.

Command-line tools are effective for opening large CSV files, but handling huge files can still be resource-intensive and may hit system limits. Besides, for those unfamiliar with terminal commands, these tools may not fully replace the convenience of traditional spreadsheets.

When dealing with huge CSV files that are too big to open any other way, databases offer a powerful alternative. By importing large CSV datasets into a database, you can efficiently query, manipulate, and view your data without hitting system memory limits or any tool’s size limit. Below, we explore three popular databases — SQLite, MySQL, and PostgreSQL — that excel at handling big CSV files.

You can utilize graphical clients to simplify working with databases. They offer user-friendly interfaces for importing, querying, and visualizing your data.

  • Multi-Database Clients:
    • DBeaver: Supports MySQL, PostgreSQL, SQLite, and more; It also includes import wizards and data visualizations.
    • HeidiSQL: Lightweight tool for MySQL and PostgreSQL with easy CSV import/export.
  • Specific Database Clients:

However, for simplicity and to keep things straightforward, we will proceed with using the CLI and services of the databases directly in the following guides.

SQLite is a lightweight, file-based database system that lets you open and query large CSV files without needing a server setup. It's an ideal choice for quickly working with big datasets, thanks to its standard SQL support and efficient data handling, all within a single local file.

Step-by-Step Guide:

  1. Install SQLite:
    • On Windows: Download the SQLite Tools for Windows from the SQLite Download page (look for sqlite-tools-win32-x86-*.zip) and extract the files to a directory of your choice.

    • On macOS: SQLite comes pre-installed on macOS. Verify by typing:

      sqlite3 --version
      

      If not installed, use Homebrew:

      brew install sqlite
      
    • Linux: Install via your distribution's package manager. For Ubuntu/Debian:

      sudo apt-get install sqlite3
      
  2. Import CSV into SQLite: To open and query large CSV files using SQLite, check out our blog post covering both GUI-based (DBeaver) and command-line methods for a visual or direct approach.

SQLite is excellent for managing large CSV files simply and efficiently. However, it does not support concurrent writes and struggles with massive file sizes, making it less ideal for high-throughput or transactional tasks. For better concurrency and performance with large CSV datasets, server-based databases like PostgreSQL and MySQL are more suitable.

MySQL is a powerful, server-based relational database designed to handle large CSV files with ease. It offers high performance, making it ideal for complex queries and data manipulations. With its scalability, MySQL is suitable for both small and enterprise-level applications, providing comprehensive SQL support for advanced querying and data analysis.

Step-by-Step Guide:

  1. Install MySQL Server: Download the MySQL Community Server from the official website.

  2. Start the MySQL Server:

    • Windows: MySQL runs as a service after installation.

    • macOS: If installed via Homebrew:

      brew services start mysql
      
    • Linux

      sudo service mysql start
      

      or

      sudo systemctl start mysql
      
  3. Log In to the MySQL Command-Line Interface (on Windows Command Prompt):

    mysql -u root -p
    

    Enter your root password when prompted.

  4. Create a Database:

    CREATE DATABASE mydatabase;
    USE mydatabase;
    
  5. Create a Table Matching Your CSV Structure:

    CREATE TABLE mytable (
      column1 VARCHAR(255),
      column2 INT,
      column3 FLOAT
    );
    

    Adjust the column names and data types to match your CSV file.

  6. Prepare for Import:

    • Ensure the CSV file is accessible by the MySQL server. For Windows, place the CSV file in a directory like C:\ProgramData\MySQL\MySQL Server 8.0\Uploads\.
    • Update the MySQL configuration file (my.ini) to set secure_file_priv to the directory containing your CSV file.
  • Import Data:

    LOAD DATA INFILE 'C:/ProgramData/MySQL/MySQL Server 8.0/Uploads/large.csv'
    INTO TABLE mytable
    FIELDS TERMINATED BY ','
    ENCLOSED BY '"'
    LINES TERMINATED BY '\n'
    IGNORE 1 ROWS;
    

    If you encounter a "secure-file-priv" error, you can use LOAD DATA LOCAL INFILE:

    mysql -u root -p --local-infile=1
    

    Then, in the MySQL prompt:

    SET GLOBAL local_infile = 1;
    LOAD DATA LOCAL INFILE 'C:/path/to/large.csv'
    INTO TABLE mytable
    FIELDS TERMINATED BY ','
    ENCLOSED BY '"'
    LINES TERMINATED BY '\n'
    IGNORE 1 ROWS;
    
  1. Query Your Data:

    SELECT column1, SUM(column2) FROM mytable GROUP BY column1;
    

This lets you process and view big CSV data efficiently.

MySQL is a robust tool for handling large CSV files, but you'll need to set up a server and manage file permissions for imports.

PostgreSQL is a powerful tool for importing large CSV files efficiently, thanks to its optimized COPY command. COPY command offers high performance for bulk data imports, along with the flexibility to handle various delimiters, quote characters, and null value options, making it a versatile choice for managing CSV files.

Step-by-Step Guide:

  1. Getting started: Download and install PostgreSQL from the official website.

  2. Start the PostgreSQL Service:

    • Linux:

      sudo service postgresql start
      
    • Windows: Open the 'Services' application, find 'PostgreSQL' in the list, right-click, and select 'Start'.

    • Mac (with Homebrew):

      brew services start postgresql
      
  3. Log in to PostgreSQL CLI:

    • Open the psql, PostgreSQL CLI:

      psql -U username -d database
      
    • If connecting to the default database:

      psql -U postgres
      
  4. Prepare the Database and Table:

    • Create a Database and connect to it:

      CREATE DATABASE mydatabase;
      \c mydatabase;
      
    • Create a Table:

      CREATE TABLE mytable (
        column1 VARCHAR(255),
        column2 INT,
        column3 FLOAT
      );
      
  5. Import CSV File Using COPY command:

    COPY mytable FROM '/path/to/large.csv'
    DELIMITER ','
    CSV HEADER;
    

    Ensure the file path is accessible by the PostgreSQL server. If importing from the client machine, use:

    \COPY mytable FROM '/path/to/large.csv'
    DELIMITER ','
    CSV HEADER;
    
  6. Query Your Data:

    SELECT * FROM mytable WHERE column2 > 1000;
    

While PostgreSQL is a powerful option for handling large CSV files, it requires server setup and configuration, making it less ideal for quick tasks.

Using PostgreSQL, you can analyze working with large CSV datasets like NYC Taxi trip data, as demonstrated in this example on GitHub.

Database setups can be complex, especially with server-based solutions like MySQL and PostgreSQL, which require configuration and permissions. On the other hand, SQLite is simpler but has its limitations. Despite this, databases are highly effective for large-scale CSV data processing.

Programming languages and their libraries allow you to build adaptable solutions tailored to your precise requirements, especially when handling complex data transformations or integrating with other systems. Below, we explore three programming languages — Python, R, and Go — that can be used to handle large CSV datasets efficiently.

Python is a versatile programming language renowned for its robust data processing capabilities. It offers powerful libraries to open and analyze large CSV files, even those too big for memory.

We'll begin with Pandas and Dask for CSV data manipulation, exploration, and joining datasets. Then, we'll introduce the Jupyter Notebook for interactive exploration.

Install Python: Before you proceed with installing libraries like Pandas and Dask, ensure that Python is installed on your system. You can download Python from the official Python website.

I. Pandas: a powerful data manipulation library with data structures like DataFrames for handling structured data.

  • Install Pandas

    pip install pandas
    
  • Read Large CSV Files in Chunks:

    import pandas as pd
    chunk_size = 100000  # the number of rows to read per chunk
    chunks = []
    for chunk in pd.read_csv('large.csv', chunksize=chunk_size):
        # Perform data processing on each chunk
        filtered_chunk = chunk[chunk['column_name'] > 100]
        chunks.append(filtered_chunk)
    # Combine processed chunks into a single DataFrame
    result = pd.concat(chunks)
    
  • However, Pandas loads data into memory, so when working with large CSV files that exceed your system's RAM, Pandas alone may not be able to handle them. You can read and process data in smaller chunks, which helps manage memory usage, but this approach may not be suitable for all types of analyses.

II. Dask: a flexible library for parallel computing in Python, that is specifically designed for out-of-core computation, allowing you to work with datasets larger than your system's memory. Dask provides a familiar DataFrame API that integrates seamlessly with Pandas but handles data in a way that distributes computations across multiple cores and manages memory efficiently.

  • Install Dask:

    pip install dask
    
  • Read and Process Large CSV Files with Dask:

    import dask.dataframe as dd
    # Read the large CSV file into a Dask DataFrame
    df = dd.read_csv('large.csv')
    # Filter the DataFrame based on a condition
    filtered_df = df[df['column_name'] > 100]
    # Compute the result, triggering the actual execution of the lazy operations
    result = filtered_df.compute()
    

R is a programming language specifically designed for statistical computing and graphics. It's highly effective for handling and analyzing large datasets, such as big CSV files. With high-performance data processing packages and advanced statistical and graphing tools, R is a desired choice for data scientists working with big data.

Step-by-Step Guide:

  1. Install R and RStudio:

    • Download R from the CRAN.
    • Install RStudio — a user-friendly IDE for R — from the official website.
  2. Use the data.table Package to Read Large CSV Files:

    The data.table package provides high-performance data manipulation capabilities, making it ideal for working with big CSV files.

  • Installation: In R or RStudio, install the data.table package by running:

    install.packages("data.table")
    
  • Usage:

    library(data.table)
    # Read large CSV file efficiently
    dt <- fread("large.csv")
    # Perform data operations
    result <- dt[column2 > 1000, .(Total = sum(column3)), by = column1]
    

The fread() function in the data.table package offers significant advantages over base R functions when working with large CSV files. One key benefit is speed, as fread() is much faster at reading large datasets compared to base R functions. Additionally, it is highly memory-efficient, designed to handle big CSV files without consuming excessive amounts of memory, making it an optimal choice for processing large-scale data in R.

  1. Use the readr Package to Parse Large CSV Files:
    • The readr package is part of the tidyverse and provides a fast and friendly way to read rectangular data, offering quicker parsing of large CSV files compared to base R functions.

    • Installation:

      install.packages("readr")
      
    • Usage:

      library(readr)
      library(dplyr)  # For data manipulation
      # Read large CSV file efficiently
      df <- read_csv("large.csv")
      # Perform data operations using dplyr
      result <- df %>%
      filter(column2 > 1000) %>%
      group_by(column1) %>%
      summarize(Total = sum(column3))
      

The read_csv() function from the readr package offers several advantages over base R’s read.csv(). In terms of performance, read_csv() is notably faster when reading large CSV files. Additionally, it provides a consistent and user-friendly interface for data import and manipulation, especially when used in conjunction with other tidyverse packages like dplyr, enhancing ease of use and workflow efficiency.

R programming language is effective for handling and analyzing large datasets when using optimized packages like data.table. However, working with datasets larger than available memory may require additional strategies or tools.

Handling large CSV files can challenge your system's resources. By adopting best practices, you can improve performance, prevent overloads, and streamline data processing. In this section, we are going to explore some technical strategies to manage large datasets efficiently.

When dealing with big CSV files, it's practical to work with a representative sample of your entire data during development and testing. This approach reduces resource consumption and speeds up the iteration process.

Example implementation: Extracting the first 1,000 lines from a large CSV file using the head command, a Linux-based tool available by default.

head -n 1000 large_dataset.csv > sample.csv

Splitting a big CSV file into smaller, more manageable parts can help you bypass the limitations of tools and streamline processing.

Example implementation: Using the split command to divide a large CSV file into chunks of 1,000,000 lines each.

split -l 1000000 large_dataset.csv chunk_

This command creates multiple files with the prefix chunk_, making it easier to open CSV files that were previously too big to handle.

Compressing large CSV files saves storage space and can improve data transfer speeds.

Example implementation: Compress a CSV file using gzip. This creates a large_dataset.csv.gz file, significantly reducing the file size.

gzip large_dataset.csv

Besides, many tools and programming libraries can read compressed CSV files directly. For example, libraries like Pandas in Python can read compressed CSV files directly:

import pandas as pd
df = pd.read_csv('large_dataset.csv.gz', compression='gzip')

Switching from CSV to columnar storage formats like Parquet. Parquet files are optimized for query performance and are more efficient to open and process when dealing with large datasets.

Example implementation: You can use Python to convert a CSV file to 'Parquet' format.

import pandas as pd
df = pd.read_csv('large_dataset.csv')
df.to_parquet('large_dataset.parquet')

If a CSV file is too big to fit in memory, processing it in chunks can prevent system overload.

Example implementation: Use Pandas to read and process a large CSV file in chunks.

import pandas as pd
chunk_size = 100000
for chunk in pd.read_csv('large_dataset.csv', chunksize=chunk_size):
    # Process each chunk
    process(chunk)

Memory mapping enables faster file I/O operations by treating file data as if it were in memory, which is beneficial for large CSV files.

Example implementation: You can use Python's mmap module as follows.

import mmap
with open('large_dataset.csv', 'r') as f:
    with mmap.mmap(f.fileno(), length=0, access=mmap.ACCESS_READ) as mm:
        for line in iter(mm.readline, b''):
            process(line.decode('utf-8'))

Utilizing multiple CPU cores can accelerate the processing of large CSV files.

Example implementation: Using Python's multiprocessing library.

import pandas as pd
from multiprocessing import Pool
def process_chunk(chunk):
    # Process the chunk
    return result
if __name__ == '__main__':
    chunk_size = 100000
    with Pool() as pool:
        results = pool.map(process_chunk, pd.read_csv('large_dataset.csv', chunksize=chunk_size))

For applications requiring real-time data processing, streaming data directly can be more efficient than batch processing.

Example implementation: Using a generator to read and process data line by line:

def read_large_file(file_path):
    with open(file_path, 'r') as file:
        for line in file:
            yield line

for line in read_large_file('large_dataset.csv'):
    process(line)
  1. How do I open a CSV file that is too large? That depends on your specific needs, resources, and the technical expertise you are willing to invest in the task. I'd say start from [here #i-excel-alternatives-for-managing-high-row-count-csv-files)
  2. What is the maximum size for a CSV file? There is no inherent maximum size for a CSV file. The practical limit depends on your computer's RAM and CPU capabilities. And, the maximum file size the software can handle without crashing, varies based on program and system configuration.
  3. How can I open a big CSV file without crashing my computer? Applications like Tad Viewer or Large Text File Viewer can open big CSV files without loading the entire content into memory. If that doesn't work, you can read and process the file in smaller sections using programming languages like Python.
  4. How do I open a large CSV file in Excel? Excel's Power Query can import data into the Data Model, bypassing Excel’s 1 million row limit. Divide the CSV file into smaller chunks that Excel can handle. Consider tools like LibreOffice Calc or dedicated CSV editors that handle larger files better.
  5. What are Excel's size limits for handling CSV files? Excel may struggle with large CSV files due to 1,048,576 rows and 16,384 columns limits. Besides, large files can exceed your system's available memory when loaded into Excel. Anyhow, Excel isn't optimized for handling extremely large datasets.
  6. How can I open a large CSV file in Access? Access can import CSV files through its wizard, but keep in mind the 2 GB database size limit. Import only necessary columns or rows to stay within size constraints.
  7. What's the best way to open a CSV file containing more than a billion rows? Utilize cloud-based data warehouses like Google BigQuery, Amazon Redshift, or Azure Synapse Analytics designed for massive datasets. You can also use frameworks like Apache Spark or Hadoop for distributed processing of large-scale data.
  8. How can I run SQL queries on a large CSV file without importing it into a database? Command line Tools like CSVkit allow SQL-like queries directly on CSV files without full database setup.
  9. How can I open a large CSV file on a computer with limited resources? Work with a subset of the data to reduce resource consumption. Remove unnecessary columns or compress the file if possible. Employ cloud services that handle processing remotely, reducing the load on your local machine.
  10. What is the difference between CSV and Excel formats (.xls or .xlsx) ? CSV files are plain text files where data is separated by commas, making them simple and widely compatible for data exchange. Excel files are proprietary formats used by Microsoft Excel that can store complex data with formatting, formulas, and macros. CSV is ideal for basic data storage and transfer, while Excel offers advanced features for data manipulation and visualization within the spreadsheet software. You can always export your Excel files into CSV to open them with all the appropriate tools we mentioned in this guide.
  11. What are other variations of the CSV file format? Tab-Separated Values (TSV), Pipe-Separated Values (PSV), Space-Separated Values (SSV), Delimiter-separated Values (DSV) with custom delimiters.

When you need to work with large CSV files:

Be Mindful of Limitations

  • Ensure your computer has sufficient RAM and CPU power to handle large CSV files.
  • Consider cloud-based solutions if your local hardware isn't adequate.
  • Recognize limitations of tools like Excel's size limit.
  • Be prepared to switch to more capable alternatives when necessary.

Choose the Right Tool

  • Excel with Power Query and LibreOffice Calc can handle big CSV files but may struggle with moderately large CSV datasets.
  • EmEditor and UltraEdit open large CSV files quickly but might lack advanced data manipulation features.
  • SQLite, MySQL, or PostgreSQL efficiently manage large datasets with powerful querying capabilities but require setup and SQL knowledge.
  • Python (with libraries like Pandas, Dask) and R offer great flexibility for advanced data processing but demand programming skills.
  • CSVkit and xsv provide quick processing of big CSV files but may have a steeper learning curve for those unfamiliar with command-line interfaces.

Implement Best Practices

  • Process data in chunks to manage memory usage and prevent system overloads.
  • Compress CSV files or convert them to optimized formats like Parquet to improve performance and reduce storage needs.
  • Utilize parallel processing by leveraging multiple CPU cores to speed up data processing tasks.

Embrace Flexibility

  • Combine different tools and methods to fit your needs.
  • If spreadsheets can't handle your file size, try specialized CSV tools or text editors.
  • For complex data manipulation, use databases or programming languages.

When one tool falls short, another can fill the gap. Effectively managing large CSV files requires a mix of the right tools, smart strategies, and an understanding of your specific needs. By thoughtfully choosing and combining solutions, you can overcome big data challenges and unlock valuable insights from your datasets. Happy data exploring!