Don's Tools · Converters · CSV to JSON & JSON to CSV

CSV to JSON & JSON to CSV

Convert between CSV and JSON both ways, right in your browser. Nothing is uploaded.

Direction
Delimiter
Works offline: the conversion runs in your browser with nothing uploaded. CSV quoting (commas and quotes inside fields) is handled, and you can switch the delimiter.
CSV to JSON and JSON to CSV is a free tool that converts tabular data between CSV and JSON entirely in your browser, with nothing uploaded. It correctly handles quoted fields containing commas, quotes and line breaks, supports comma, semicolon and tab delimiters, lets you treat the first row as a header and pretty-print the JSON, and you can copy or download the result.

Frequently asked questions

Is my data uploaded anywhere?

No. The conversion runs entirely in your browser and nothing is uploaded, so even sensitive spreadsheets stay on your device. It works offline once loaded.

Does it handle commas and quotes inside fields?

Yes. The CSV parser follows the usual rules, so fields wrapped in double quotes can contain commas, line breaks and escaped quotes, and they are read and written correctly.

Can I use a semicolon or tab delimiter?

Yes. Switch the delimiter to comma, semicolon or tab. This applies to both reading CSV and writing CSV.

What JSON shape does it expect for JSON to CSV?

An array of objects works best, where each object becomes a row and the keys become columns. A single object or an array of arrays also works. Nested values are written as compact JSON inside the cell.

Why do I get a parse error?

For CSV to JSON the text must be valid CSV; for JSON to CSV it must be valid JSON. The message tells you what went wrong so you can fix the input.