CSV ⇄ JSON Converter
Free online CSV ⇄ JSON converter: first row becomes the header, with quoted fields, escaped commas and embedded newlines supported, plus automatic number and boolean detection.
How to Use
- Pick a direction
Choose CSV → JSON or JSON → CSV; the input box fills with a matching sample.
- Paste your data
Use field names in the first CSV row, or an array of objects for JSON — results update live.
- Check rows and copy
Verify the reported row and column counts, then copy the result.
FAQ
Are commas inside CSV fields treated as separators?
No. Double-quoted fields such as "Shanghai, CN" are read as a single value, and a doubled quote inside a field ("") is restored to one quote.
Do numbers become strings?
With 'Detect numbers and booleans' ticked (default), plain numbers become numbers, true/false become booleans and null becomes null. Untick it to keep everything as strings.
How is the CSV header decided?
Keys are collected as a union in order of first appearance. Rows missing a field simply get an empty cell.
What if my JSON is invalid?
The tool shows the browser's parse error. JSON must be an array of objects such as [{...}, {...}]; a single object or any non-array structure is rejected with a clear message.