Free Developer Tools — JSON, Base64, JWT, Regex
43 client-side developer utilities: JSON formatter, Base64, JWT, regex tester, minifiers, converters, and more. No paste-to-server risk.
Secrets in JWTs, API dumps, and config files stay local. These tools use pure JavaScript APIs — nothing is POSTed to a backend.
43 free tools in this category · zero accounts · zero tracking · works offline as a PWA after first visit.
Why on-device dev tools?
Most “free online tools” upload your files to a cloud worker, store them temporarily, and hope their privacy policy holds. Just Tool It takes the opposite approach: zero-server processing. Your browser loads a static page and runs open client-side libraries. That means no sign-up wall, no file retention risk, and no surprise data mining — ideal for sensitive documents, photos, tokens, and personal data.
How it works
- Pick a tool from the list above.
- Drop a file or paste text — it stays in this browser tab.
- Download the result. Close the tab and the in-memory data is gone.