Comma-Separated Values (MIME: text/csv) is the simplest and most universal data exchange format, storing tabular data as plain text with values separated by commas. It can be opened by virtually any spreadsheet application, text editor, database tool, or programming language.
History and Development
The CSV (Comma-Separated Values) format has roots dating back to the 1970s when it was used for data interchange between mainframe computers. There is no single formal standard — RFC 4180 (2005) provides the most widely followed specification. Despite (or because of) its simplicity, CSV has remained the most common format for data import/export across all platforms for over 50 years.
Technical Specifications
- Format: Plain text with comma delimiters
- Encoding: UTF-8 (recommended), ASCII, or other encodings
- Delimiter: Comma (,) by default; semicolons common in European locales
- Quoting: Double quotes for fields containing commas or newlines
- Header row: Optional first row with column names
- Max size: No formal limit (limited by application)
- Data types: All values stored as text strings
Common Use Cases
CSV is the universal format for data exchange between applications. It's used for database imports/exports, spreadsheet data sharing, analytics tool inputs (Python pandas, R), CRM/ERP data migration, financial data feeds, email list management, and bulk uploads to web applications.
CSV vs Similar Formats
- CSV vs XLSX: CSV is plain text (universal, small, no formatting); XLSX supports formulas, formatting, charts, and multiple sheets.
- CSV vs JSON: CSV is tabular (rows and columns); JSON supports nested/hierarchical data. CSV is better for spreadsheets; JSON for APIs.
- CSV vs TSV: TSV uses tabs instead of commas, avoiding issues when data contains commas. Both are plain text.
How to Open and Edit
CSV opens in Excel, Google Sheets, LibreOffice Calc, Numbers, and any text editor. Programming languages like Python (pandas, csv module), R, and JavaScript can parse CSV natively. Database tools can import CSV directly.
Frequently Asked Questions
Why does my CSV look wrong in Excel?
Excel may misinterpret the delimiter (especially in European locales where semicolons are used) or the encoding (try UTF-8 BOM). Use File > Open > Text Import Wizard for more control.
Can CSV store formulas or formatting?
No. CSV is plain text only — no formulas, colors, bold text, or cell formatting. For those features, use XLSX format.
What is the maximum row limit for CSV?
CSV itself has no row limit. However, Excel can only open CSVs with up to 1,048,576 rows. For larger datasets, use Python pandas, database tools, or other programming approaches.