Developer Tools
JSON ⇆ CSV.
Convert JSON to CSV or CSV to JSON. Nested objects flatten to dot-notation columns and unflatten back on the way in. Everything runs in your browser — nothing is uploaded.
Input
Output
Paste or upload data, then press Convert.
How it works
- JSON → CSV: an array of objects becomes rows; nested objects flatten to
parent.childcolumns; nested arrays are stored as JSON text in the cell. - CSV → JSON: the first row is read as headers; dot-notation headers (
address.city) unflatten back into nested objects; numbers and booleans are detected automatically. - On-device: parsing and conversion happen entirely in your browser. No file is ever uploaded to a server.
Free vs Premium
This tool is fully free with no cap on input size or number of conversions — a data converter doesn't need a paywall to be useful.