Key features
- Auto-detects and formats any valid JSON page
- Collapsible, indented tree view
- Syntax highlighting for keys, strings, numbers, and booleans
- Toggle between raw and formatted view
- Clickable URLs found inside JSON values
- Exports parsed JSON to window.json for console use
- Control/Cmd-click to collapse all sibling nodes at once
What JSON Formatter does
JSON Formatter watches for pages that return valid JSON, whether that's an API endpoint, a local .json file, or a raw text response, and rewrites the display as an indented, color-coded, collapsible tree. Instead of scrolling through one dense line of text, you can expand and collapse objects and arrays, click through nested URLs, and read the structure at a glance.
JSON Formatter free vs paid
JSON Formatter has no paid tier. Every feature, including dark mode, collapsible trees, syntax highlighting, and the raw/formatted toggle, is available for free with no account or upgrade prompts. The developer states the extension has no tracking or advertising built in.
Is JSON Formatter safe?
The extension needs to read page content to detect and reformat JSON, but the developer explicitly states there's no tracking, no advertising, and data isn't sold or used for unrelated purposes. It's open source, so the code handling your data can be reviewed directly on GitHub.