JSON Indenter

JSON Formatter Bookmarklet

Install the JSON Formatter & Validator Bookmarklet to format any JSON URL with a single click.

Last Updated: January 30, 2026

Install the JSON Formatter & Validator Bookmarklet to quickly and easily format and validate any public JSON URL with a single click.

Drag this to your bookmarks toolbar

JSON Formatter

Simply drag the button above into your bookmarks toolbar.

How it works

  • 1. Install: Drag the "JSON Formatter" button into your browser's bookmarks bar.
  • 2. Browse: Navigate to any public JSON API endpoint or raw JSON file (e.g., on GitHub).
  • 3. Click: Click the bookmarklet to instantly load that JSON into our formatter for cleaning and validation.

Why use it?

  • Speed: No more copying and pasting long JSON strings.
  • Security: Our tool runs entirely on your machine, just like always.
  • Validation: Automatically find syntax errors in API responses.

CORS Note

The bookmarklet works best for public APIs. If an API requires authentication headers or specific cookies that aren't present in the browser session, the direct fetch might fail. In such cases, standard copy-pasting is recommended.