JSON Formatter & Validator – Free Online Tool

Boost your productivity with the fastest online JSON Formatter & Validator. Instantly beautify, validate, and repair malformed JSON so you can debug APIs, configuration files, and webhooks in seconds.

Why developers choose our JSON Formatter

• ✅ Instant JSON beautifier – paste minified JSON and get perfectly indented, color-coded output.
• ✅ RFC-compliant JSON validator – checks against RFC 8259, ECMA-404, and legacy RFC 4627 standards.
• ✅ Smart JSON repair – auto-corrects quotes, commas, comments, unescaped characters, and numeric keys.
• ✅ Zero-install – runs entirely in your browser; no sign-up, no download.
• ✅ Mobile-friendly – clean UI interface that works on phones, tablets, and desktops.

How it works

1. Paste raw or broken JSON into the editor.
2. Click Format for pretty-printed JSON or Minify to compress.
3. Toggle Validate & Repair to fix syntax errors automatically.
4. Copy the cleaned JSON with one click and resume coding.

Built for real-world debugging

From API responses and MongoDB dumps to VS Code settings, our online JSON validator handles any payload size—fast. Whether you’re troubleshooting a REST API, debugging WebSocket messages, or reviewing GitHub Actions YAML, format and validate JSON on the fly and ship cleaner code.

100 % free, open-source friendly

This tool is maintained by Nnaemeka Nweke who needed a reliable JSON formatter online without intrusive ads or data collection. Bookmark it, share it, and keep debugging at the speed of light.

Ready to clean your JSON? Paste your code above and see the difference instantly.