JSON Lab: Fast Online JSON Tools for Developers

Format, validate, diff, convert, and visualize JSON in your browser. No login required, mobile-friendly, and designed for large files.

Browse tutorials in Docs and common questions in FAQ.

JSON Editor

Paste JSON, get instant formatting, linting, folding, and a safe preview for large inputs.

Open the in-browser editor
Loads only when needed to keep initial page render fast.

More Tools

Speed up daily JSON work with purpose-built utilities and clean shareable outputs.

  • JSON to XML — Convert data for legacy systems and integrations.
  • JWT Decoder — Inspect JWT headers and payload safely in-browser.
  • Base64 Encoder — Encode/decode strings with UTF-8 support.
  • URL Encoder — Encode/decode query strings reliably.

Visualize and Learn

Turn complex JSON into a readable structure and learn best practices from short, practical articles.