CSV ⇄ JSON Converter
Paste a CSV to turn it into JSON, or a JSON to turn it into CSV. Choose the delimiter (comma, semicolon or tab), whether the first row is the header and whether to detect numbers and booleans. Everything happens in your browser: your data is never uploaded to any server.
How to convert CSV and JSON
- Paste your CSV or your JSON into the box on the left.
- Choose the conversion direction (CSV→JSON or JSON→CSV).
- Adjust the options: delimiter, first row as headers and type detection.
- Press “Convert” and check the result on the right.
- Copy the result or download it as a .json or .csv file.
Frequently asked questions
Is my data uploaded to any server?
No. The conversion happens entirely in your browser with JavaScript. Your CSV or JSON is never sent over the internet.
Does it handle commas and quotes inside the values?
Yes. The parser follows the CSV standard (RFC 4180): it respects quoted fields, commas and line breaks inside quotes, and escaped quotes such as "".
Which delimiters does it support?
Comma (,), semicolon (;) and tab. The semicolon is common in spreadsheets from regions where the comma is the decimal separator.
Does it convert numbers and booleans automatically?
If you enable “Detect numbers and booleans”, values like 42 or true are converted to number and boolean in the JSON. To avoid corrupting data, they are only converted when it is safe: text like 007 or codes with leading zeros are kept as a string.
How does it convert JSON to CSV?
If the JSON is a list of objects, it uses the union of all keys as headers. If it is a list of lists, each list is a row. Nested values (objects or arrays) are serialized inside the cell.
Does it work offline?
Yes. Once the page has loaded, all the conversion happens locally, so it works without internet.