Convert JSON to CSV (and back)

How it works

This tool is designed for developer or data use: you get an API response (a JSON array of objects) and need to open it in Excel or Google Sheets to analyze it or share it with a non-technical team — paste the JSON, click "JSON → CSV" and download or copy the resulting table. In the other direction, if you're preparing a test dataset for a script or an API payload from a spreadsheet exported as CSV, "CSV → JSON" rebuilds a JSON array of objects directly usable in your code.

What happens if my JSON contains nested objects?

Nothing is lost: a nested value (object or array) is kept as-is, as compact JSON text, in the corresponding CSV cell. The column therefore still exists, but its content remains "raw" JSON rather than being split across several columns.

Can I convert the generated CSV back into JSON identical to the original?

Not quite identically. CSV has no native types: when converting back to JSON, all values (including numbers and booleans) become strings again, and a nested object reappears as a string containing JSON text rather than as a native object. The structure and data are preserved, but not the original types.

As with all Onvera tools, the conversion runs 100% locally in your browser thanks to WebAssembly: your JSON or CSV data is never sent to a server.