data conversion tools
100% offline
No uploads
Free · no signup
2 tools
Data tools
Offline data conversion tools transcode between common structured formats — CSV, JSON, HTML tables — entirely in the browser using streaming parsers, so even multi-megabyte datasets convert without uploading a single byte.
Every Data tool
About data conversion tools
Data conversion is exactly the kind of operation where uploads should not happen. The file is often an export from a private system: a customer list, a financial export, an internal report. These tools accept files via drag-and-drop, parse them with streaming libraries (PapaParse) in the browser, and emit the converted output for you to download. Verify with DevTools → Network: zero requests fire.
Why pick offline data conversion tools
- Zero uploads — data never leaves your browser
- Zero tracking — no analytics, ads, cookies, or fingerprinting
- Free, no signup or account required
- Works offline once loaded; installable as a PWA
- Verifiable in DevTools — zero network calls when you press a button
Frequently asked questions
Are these data conversion tools safe for production data?
Yes — the file you drop is parsed in your browser and never uploaded. Open DevTools → Network to confirm zero requests fire when you load and convert a file.
How large a CSV can I convert?
The browser is the only limit. Multi-megabyte CSVs convert in seconds because we use PapaParse's streaming mode plus virtualised rendering for table previews. We have tested files up to ~50 MB without issue on modern hardware.
What delimiters and quoting rules does the CSV parser handle?
Comma, semicolon, tab, and pipe delimiters are auto-detected. Quoting follows RFC 4180 — fields wrapped in double quotes can contain commas, embedded newlines, and escaped double quotes ('""') without breaking parsing.