Format, validate, and debug JSON. Entirely in your browser.Open DevTools -> Network. You'll see zero requests. That's the whole point.
Handles 50MB+ JSON files that crash VS Code. All in your browser. No upload.
In November 2025, popular online JSON tools were caught leaking over 80,000 credentials, including AWS keys, GitHub tokens, and bank details. SafeJSON runs 100% client-side. Open DevTools -> Network, format once -> zero new requests.
Handles files up to 50MB locally - no upload, no slowdown.
{ }
Paste JSON on the left, see it formatted here
Cmd+Enter to format
We don't ask you to trust us. Open DevTools -> Network tab -> paste any JSON. Zero requests. Your data never left your browser. Formatter, diff, JWT decoder, and JSONPath work the same way.
No loading spinners. No waiting. Paste your JSON and see formatted output immediately.
Tree view with collapsible nodes, error location with line numbers, dark mode, keyboard shortcuts. No clutter, no ads.
The entire codebase is on GitHub. You can audit every line. No obfuscated tracking scripts. No surprises.
Core formatting, validation, and tree view are always free. Advanced tools like JSON diff, JWT decoder, JSONPath, and Schema are optional Pro features.
Auto-detect and format JSON responses on any URL. Available on Edge Add-ons. No tracking, no data collection.
Advanced tools for developers who work with JSON every day. All client-side, all privacy-first.