Convert JSONL to CSV
Turn JSONL into CSV on your own machine — the file never leaves your computer.
- runs locally
- no upload
- no signup
Drop files here, or click to choose
Batch selection supported. You can also paste files (Ctrl+V / Cmd+V).
Queue
Kept on this device for 24 hours
Converted files stay in this device’s browser and are deleted after 24 hours. They never reach the server and are not shared with other sites or devices.
Belongs to this address and this browser only: other module subdomains, devices or browser profiles cannot see it.
Results above 64 MB are not stored here — download those right away.
Nothing kept right now.
Supported conversions
| From | To |
|---|
Everything runs locally. More formats are added over time.
Worth knowing
- Conversion runs inside the browser; the server never receives the file.
- Keys become the header as a union; missing fields stay empty.
- Nested objects and arrays are written into the cell as JSON text, so nothing is lost.
- The delimiter is detected automatically (comma, semicolon, tab) and can be set by hand.
- Commas, newlines and quotes inside fields are escaped per RFC 4180, so Excel keeps the columns.
- Drop a batch and convert them together, then download everything as one zip.
- Keep single files under 2 GB and batches under 60 files.
- No third-party scripts are loaded and results are never collected.
How it works
- Drop files into the box above, or use the file picker. Pasting works too.
- The target format is preselected for this page. Change it per file if you want.
- Press convert, then download files one by one or as a zip.
Questions
Are my files uploaded?
No. Conversion uses the decoding and encoding built into your browser, and nothing is sent to the server. Open the Network panel in devtools to check for yourself.
Why is there no signup?
The server only serves a static page; it never touches your files. Without accounts there is nothing to log in to.
Can it handle batches?
Yes. Drop a batch, pick a target per file, then download individually or as a single zip.
Is nested data lost?
No. Nested objects and arrays land in the cell as JSON text and convert back unchanged.