FixFile
File Format

CSV (.csv)

Comma-Separated Values — the simplest and most universal data exchange format. Stores tabular data as plain text rows, readable by every spreadsheet application and database.

Extension
.csv
MIME Type
text/csv

Last updated

Overview

CSV (Comma-Separated Values) is a plain-text format for storing tabular data: rows of values separated by commas (or other delimiters like semicolons or tabs). It has no official standard, though RFC 4180 describes a commonly used convention. CSV is the universal data interchange format — every database, spreadsheet application, BI tool, and data processing script can read and write CSV without conversion.

The simplicity of CSV is its greatest strength. A CSV file opened in any text editor reveals exactly what it contains: column headers on the first row, data on subsequent rows. This transparency makes CSV ideal for data migration, API responses, system exports, and any scenario where one application needs to hand off structured data to another.

Common Uses

  • Data export and import — databases, CRMs, ecommerce platforms, and SaaS tools export data as CSV
  • Spreadsheet data exchange — sharing data between Excel, Google Sheets, LibreOffice, and Numbers
  • ETL pipelines — Extract-Transform-Load data workflows use CSV as the intermediate format
  • Configuration data — lookup tables, product catalogs, and reference data stored as CSV
  • Machine learning datasets — training data for ML models is commonly distributed as CSV

Advantages

  • Universal compatibility — every tool that handles data can import and export CSV
  • Human-readable — open in any text editor to inspect and edit data directly
  • Zero overhead — no proprietary structure, no version compatibility issues, no special software needed
  • Tiny file size — pure text with no formatting means compact files even for millions of rows

Limitations

  • No data types — everything is stored as text; numbers, dates, and booleans require parsing by the application
  • No formatting — no fonts, colours, formulas, or charts
  • Delimiter conflicts — values containing commas must be quoted; inconsistent quoting causes parsing errors
  • Encoding issues — CSV files from non-English systems may use different encodings (UTF-8 vs Windows-1252), causing character corruption (mojibake) when opened in Excel
  • Single sheet — one CSV = one table; cannot represent multi-sheet workbooks

Supported Software

  • Spreadsheets: Microsoft Excel, Google Sheets, LibreOffice Calc, Apple Numbers
  • Databases: MySQL, PostgreSQL, SQLite, SQL Server (BULK INSERT)
  • Programming: Python (csv module, pandas), R, JavaScript, virtually every language