JSON ⇄ CSV Converter

Two directions, one tool: JSON arrays become spreadsheets, CSV files become API-ready JSON.

Why convert between JSON and CSV?

APIs speak JSON; spreadsheets speak CSV. Moving data between them is one of the most common data chores: exporting API results into Excel, loading a customer list into an app, or archiving query output. This tool flattens nested objects to their string form, unions all keys across rows into a single header row, and quotes fields that contain delimiters — the parts that trip up hand-written conversions.

Frequently asked questions

What about nested JSON objects and arrays?

Nested values are kept as JSON text inside their cell (double-quoted), so nothing is lost — round-tripping back to JSON restores the structure.

Is my data uploaded?

No. Conversion happens in your browser. Customer lists and API responses with private data never leave your device.