JSON ↔ CSV Converter

Convert between JSON and CSV in your browser. Handles nested objects, type inference, and large files. No server upload.

JSON Input

Open file

CSV Output

JSON → CSV options Flatten nested objects (a.b) Delimiter

About this tool

Convert between JSON and CSV without leaving the browser. Powered by Papa Parse, which handles quoting, escaping, multi-line cells, and large files correctly. Files you load never leave your machine.

JSON → CSV

Input must be an array of objects (the typical "table-like" JSON shape).
Optionally flattens nested objects using dot notation, so { "user": { "id": 1 } } becomes a column called user.id.
Columns are inferred from the union of keys across all rows.

CSV → JSON

Auto-detects the delimiter by default, or pick one explicitly.
Optional type inference converts "42" → 42, "true" → true, empty cells → null.
Without a header row, output is an array of arrays instead of an array of objects.