JSON Viewer
Browser Extension 2026-04-03
A browser extension that highlights and formats JSON/JSONP content. Fork of tulios/json-viewer, modernized with Manifest V3 and multi-browser support.
#Chrome#Edge#Firefox#Safari#JSON
JSON Viewer
Introduction
JSON Viewer is a browser extension that automatically detects and syntax-highlights JSON and JSONP content on web pages. It is a maintained fork of the original JSON Viewer by Tulio Ornelas, modernized to work with current browsers using Manifest V3 and the WXT framework.
Key Features
- Syntax highlighting with 27 built-in themes
- Collapsible/foldable nodes
- Clickable URLs within JSON values
- Line numbers and search
- Sort keys alphabetically
- Works with JSONP responses
- Handles numbers larger than Number.MAX_VALUE
- Customizable themes, tab size, and CSS
- Omnibox integration (Chrome/Firefox)
- Scratch pad for formatting arbitrary JSON
Supported Browsers
- Chrome
- Firefox
- Safari
Support
If you have questions, feature requests, or found a bug, please open an issue on GitHub (recommended). You can also reach out via email at rxliuli@gmail.com.
Privacy
This extension processes all content locally. It does not collect or transmit any user data.