CSV ↔ JSON

Move between CSV and JSON, losslessly.

Convert a CSV table into an array of flat JSON objects, or an array of flat objects back into CSV. Values are treated as text, so IDs and leading zeros arrive intact.

Direction

Drop a CSV or JSON file

Up to 5.00 MB — or paste below.

Choose a file

How it works

  1. 01Open a .csv or .json file, or paste the content.
  2. 02Pick the direction and, for CSV, the delimiter and header row.
  3. 03Problems such as duplicate or empty headers are reported before any conversion.
  4. 04Preview the result and download it.

Supported shapes

JSON → CSV needs an array of flat objects, for example [{"id":"001"}]. Nested objects and arrays are rejected with the exact field named, rather than flattened or dropped.

Questions & limits

Are numbers converted to JSON numbers?
No. Every CSV value becomes a JSON string, which is the only way to keep 00123, long order IDs and phone numbers exactly as written.
What happens with duplicate headers?
The conversion stops and names the duplicated columns. Otherwise one column would silently overwrite the other.
Can it handle nested JSON?
Not for JSON → CSV. CSV is a flat format, so nested objects and arrays are reported with their field name so you can flatten them first.
Is anything uploaded?
No. Parsing and conversion happen in this browser tab and the content is dropped as soon as you reset or close the page.