About this tool
CSV is what the world exports; JSON is what your code wants. CSV ↔ JSON Converter moves data both directions without leaving your browser. Paste CSV or drop a file, choose the delimiter — comma, semicolon, tab or pipe — and decide whether the first row is a header. With headers on, each row becomes a JSON object keyed by column name; without them, rows become arrays. Optional type inference turns numeric-looking cells into numbers, true and false into booleans and empty cells into null, so the output is ready to feed an API rather than a wall of strings. Going the other way, paste a JSON array of objects and the tool flattens the union of keys into a header row and emits clean, properly quoted CSV that Excel and every importer will accept. The parser follows RFC 4180, so quoted fields, embedded commas and multi-line cells survive intact, and conversion errors are reported with row numbers instead of silent corruption. Sizable files convert instantly because the work happens on your machine — which is also why this is the right place for customer exports, financial data and anything else your compliance team would rather not see pasted into a server-side converter.
How to use CSV ↔ JSON Converter
- Choose the direction: CSV to JSON or JSON to CSV.
- For CSV input, set the delimiter and whether the first row is a header row.
- Paste the data (or drop a file for CSV) and the conversion runs instantly.
- Copy the result or download it as a .json or .csv file.
Frequently asked questions
How does type inference work?
When enabled, cells that look like numbers become JSON numbers, true and false become booleans, and empty cells become null. Disable it to keep every cell a string exactly as written.
Are quoted fields with commas handled?
Yes. The parser follows RFC 4180: quoted commas, double-quote escapes and newlines inside quoted fields all parse correctly.
What JSON shapes work for JSON-to-CSV?
An array of flat objects (the common case) or an array of arrays. For objects, the header row is the union of all keys; nested values are serialized as JSON text inside the cell.
Is my data uploaded?
No. Parsing and serialization run entirely in your browser. Customer exports and financial data never leave your machine.