JSON vs CSV vs XML: Which Data Format to Use
How JSON, CSV and XML compare for storing and exchanging data — structure, readability, size and best use cases — with free converters.
JSON, CSV and XML are the three most common ways to store and exchange data. They overlap, but each shines in different situations.
Quick answer
- CSV — best for tabular data (rows and columns) headed to a spreadsheet.
- JSON — best for structured/nested data and web APIs.
- XML — best when you need strict schemas, namespaces or document markup.
The comparison
| CSV | JSON | XML | |
|---|---|---|---|
| Structure | Flat table | Nested (objects/arrays) | Nested + attributes |
| Readability | High (simple) | High | Verbose |
| File size | Smallest | Small | Largest |
| Data types | All text | Numbers, booleans, null | All text (unless schema) |
| Best for | Spreadsheets | APIs, config | Documents, enterprise |
CSV: simple and compact
CSV is just rows of comma-separated values. It's the smallest and simplest, opens directly in Excel or Google Sheets, but it can't represent nested data and everything is text (no real types).
JSON: the web's default
JSON handles nested objects and arrays, distinguishes numbers, booleans and null, and is what almost every modern API speaks. It's readable and compact — the go-to for configuration and data exchange on the web.
XML: strict and self-describing
XML supports attributes, namespaces and schema validation (XSD), which matters in enterprise systems, document formats (like DOCX) and SOAP APIs. The cost is verbosity — it's the largest and wordiest of the three.
Convert between them for free
- JSON to CSV and CSV to JSON
- JSON to XML and XML Formatter
- JSON Formatter & Validator — beautify and check JSON
Everything runs in your browser — paste your data, convert, and copy the result without uploading anything.