Convert JSON to CSV
An array of objects becomes one column per key. Nested objects are written as JSON text in the cell rather than being silently flattened or dropped.
- Runs entirely in your browser
- Works offline
- No upload
- No sign-up
- No watermark
Loading the tool…
How it works
- Drop a .json file, or paste the JSON.
- Choose CSV, TSV or Excel, and whether to add a BOM.
- Download the result.
Why nothing is uploaded
Every operation on this page is done by code running inside your browser tab, using the same engine that renders web pages. The file is read from disk into your tab’s memory, transformed there, and written back out as a download. It is never sent anywhere — not to us, not to a third party.
Verify it yourself
- Open your browser’s developer tools (F12) and select the Network tab.
- Load your file and run the tool.
- The only requests you will see are the tool’s own code and, once cached, none at all.
Frequently asked questions
What is the BOM for?
Excel on Windows assumes the system codepage unless a CSV starts with a UTF-8 byte-order mark. Without it, Japanese column names open as mojibake. It is on by default because that is the failure people actually hit.
What happens to nested objects?
They are written into the cell as JSON. Flattening them into dotted column names guesses at your intent and loses arrays, so the tool keeps the data instead.
Is my document uploaded?
No. It is parsed and converted inside this browser tab. Load the page, disconnect, and it still works — which is the only guarantee worth having for a contract or a customer list.