Free JSON to CSV Converter, No Sign-up and Nothing Uploaded
This free JSON to CSV converter flattens a list of JSON records into a table you can open in a spreadsheet. There is no sign-up or login, no watermark, and no upload: your JSON is processed in your browser and never leaves your device.
It suits API responses, logs and exports that you want to sort, filter or share with someone who works in Excel or Google Sheets. Records that share the same fields convert most cleanly.
- Free
- No sign-up
- Never uploaded
- No watermark
Your files are converted on your device and never uploaded.
How to convert
- Drag your JSON files onto the page or choose them with the file picker.
- Pick CSV as the target format.
- Check the options, then start the conversion.
- Download each CSV, or take a batch as one ZIP.
Features
- Runs natively in your browser with no engine download.
- Works best with a list of records that share the same fields.
- Output opens in any spreadsheet app.
- Batch conversion of several files.
- No watermark and no account.
Supported formats
About the formats
Flattening JSON into a table
JSON can nest objects and lists inside each other, while CSV is a flat grid. The converter works best on an array of similar records, where each record becomes a row and each field a column. Deeply nested or uneven data does not fit a table neatly and may need reshaping first.
JSON keeps types such as numbers and booleans, but CSV stores everything as text.
Privacy: how it works
- Your JSON files stay on your device. The page reads each file with the browser's file API, converts it with code running in the tab, and hands the result back as a download. No upload happens, so there is no copy of your file on our servers to protect, delete or leak.
- There is nothing to sign up for and no login. The converter does not ask for an email address, and it does not need to know who you are to do its job.
- You can check the claim yourself: open your browser developer tools, watch the Network tab while a file converts, and you will see no request that carries your file.
- API responses often contain tokens or personal details. Parsing happens in the tab, so the content is not copied to any server.
Tips
- Start with an array of objects that share the same keys for the cleanest table.
- Flatten deeply nested data in your source before converting if you need every value in its own column.
- Check the header row of the result to confirm all fields were picked up.
- Expect booleans and numbers to become plain text in the CSV.
- Validate that the JSON is well formed, since a missing comma or quote will stop parsing.
Frequently asked questions
Is it really free?
Yes. There is no price, no trial, no credit card and no watermark added to your results. Ulkaa Tool does the conversion with your own device, so there is no server bill to pass on to you.
Are my files uploaded?
No. Your JSON files are read and converted inside your browser and are never sent to Ulkaa or to anyone else. The result is created on your device and you save it from there.
Do I need an account?
No. There is no sign-up and no login. Open the page, add your files and convert. An Ulkaa account is not needed for anything on this tool.
Is there a file size limit?
No limit is set by us. The real limit is your device: the conversion uses your own memory and processor, so very large files can be slow, and a very big batch may need to be split into smaller runs.