JSON Formatter

Tracking since Apr 1, 2026.

Changelog

• May 18, 2026
  description

  Automatically prettifies any JSON response opened in a browser tab.
  
  FEATURES:
  -  **Fast**, even on very long JSON pages
  -  Dark mode support
  -  Syntax highlighting
  -  Code folding and indent guides
  -  Clickable URLs
  -  Raw/Parsed toggler
  
  JSON Formatter is proud to support Code.org, a nonprofit that supports our mission to help everyone become better coders.  We invite you to help our mission when you are shopping at partner stores, at no cost to you.  Support is always optional, and can be permanently disabled at any time.  We may get paid commissions from companies and/or affiliate programs on sites visited and/or products purchased while using this browser extension.  These commissions/affiliate-payments become the donations that go to your selected charity.

  The original JSON Formatter, now with optional dark mode 🌚
  
  Auto-formats JSON when you load it in a browser tab.
  
  FEATURES
  
  - Fast, even on very long JSON pages
  - Dark mode
  - Syntax highlighting
  - Collapsible trees, with indent guides
  - Clickable URLs
  - Negligible performance impact on non-JSON pages (less than 1 millisecond)
  - Works on any valid JSON page – URL doesn't matter
  - Buttons for toggling between raw and parsed JSON
  - FIXED: Exports the parsed JSON to window.json so you can explore it in Dev Tools
  
  Note: this extension might clash with other browser extensions that modify the DOM before it runs. If it doesn't seem to be working, try disabling other extensions. If it clashes with an extension you need, open an issue and I'll try to find a solution.
  
  SOME EXAMPLE JSON PAGES to try it out on:
  https://callumlocke.github.io/json-formatter/
  
  PRO TIP
  Hold down control (or cmd on Mac) while collapsing a tree - collapses all siblings too.
  
  PRIVACY
  No tracking, no advertising, and nothing else nefarious.
  
  SOURCE CODE
  github.com/callumlocke/json-formatter
  
  ISSUES
  github.com/callumlocke/json-formatter/issues

• May 18, 2026
  short_description

  Makes JSON easy to read and explore

  Makes JSON easy to read

• May 18, 2026
  permissions

  storage, unlimitedStorage, webRequest

  storage

Permissions & access

Permissions

storage

Host access

*://*/*, <all_urls>

Screenshots

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