JSON Formatter for Chrome: Readable JSON with Dark Mode
JSON Formatter · for Windows, macOS and Linux
Developer: Callum Locke (opens in a new tab)
- Windows
- macOS
- Linux
The download link points to the program’s official source; the file is not hosted on this site. Link address: chromewebstore.google.com
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JSON Formatter is a free, open-source Chrome extension by Callum Locke that automatically formats JSON opened in a browser tab, with syntax highlighting, collapsible trees and an optional dark mode.
Open a raw API response in Chrome and you often get a wall of text on a single line. JSON Formatter turns it into an indented, colored tree that you can fold and unfold.
Features
- Automatic formatting: Any valid JSON page is formatted when it loads, whatever the URL.
- Fast on large files: Designed to stay quick even on very long JSON pages, with negligible impact on non-JSON pages.
- Syntax highlighting and dark mode.
- Collapsible trees with indent guides.
- Clickable URLs inside the data.
- Raw/parsed toggle: Switch between the original text and the formatted view.
- window.json: The parsed data is exposed in DevTools so you can explore it from the console.
Pro tip from the developer: hold Ctrl (Cmd on a Mac) while collapsing a node to collapse all its siblings too.
Privacy
The listing promises no tracking and no advertising. The source code is on GitHub at callumlocke/json-formatter, where you can also report issues.
Installing it
- Click Download to open JSON Formatter on the Chrome Web Store. Several extensions share the name; this is the one published by Callum Locke.
- Add it to Chrome.
- Open any JSON URL to see it formatted.
If it doesn’t seem to work, another extension that modifies pages may be clashing with it; try disabling others. Developers will also like React Developer Tools and Web Developer.
Pros
- Formats JSON automatically and quickly
- Dark mode and collapsible tree
- No tracking or ads
Cons
- Can clash with extensions that modify pages
- Only formats; it does not edit JSON
Frequently Asked Questions
Why is my JSON not being formatted?
The page must contain valid JSON. Another extension that changes pages before JSON Formatter runs can also interfere, so try disabling other extensions.
Can I see the original raw JSON?
Yes. Buttons on the page switch between the raw text and the parsed, formatted view.
JSON FormatterOpen source
Download (opens in a new tab)
