Fast JSON viewer - highlights, shows items count/size, handles large files

  • JSON Lite
  • JSON Lite
What is JSON Lite?
JSON Lite is a user-friendly Firefox add-on designed for handling JSON/JSONP easily. It can outline arrays, objects, long values and also helps in encoding and decoding. JSON Lite is capable of showing large (10MB+) and even invalid JSON files. It provides the feature to count items and properties in the collection and displays their sizes. It also retains the original sequence of numeric keys, avoiding rounding off large numbers. Additionally, the 'Save as' feature enables saving the original JSON document.
Rating: 4.49 (100)
Version: 21.3.0 (Last updated: 2021-03-03)
Creation date: 2016-10-14
Weekly download count: 202
Firefox on Android: Yes
Risk impact: High risk impact
Risk likelihood: Low risk likelihood
Manifest version: 2
  • contextMenus
  • storage
  • tabs
  • webRequest
  • webRequestBlocking
  • <all_urls>
Size: 27.98K
URLs: Website
Stats date:

Other platforms

JSON Lite (v24.5.0)
4.86 (51) 10,000
Not available on Edge
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Disable Firefox built-in JSON viewer first - go to about:config page and set 'devtools.jsonview.enabled' to false


  • Format JSON/JSONP responses and clipboard
  • Select and format/encode/decode text on every page
  • Collapsible arrays, objects and long values
  • Collapse all childs with Ctrl(Command) + Click
  • Collapse property also on all sibling items with Alt(Option) + Click
  • Count items and properties in a collection
  • Show collection sizes
  • Do its best to show large (10MB+) JSON files
  • Do its best to show invalid JSON files
  • Do not sort objects with numeric keys
  • Do not round large numbers
See more
User reviews
User reviews summary
These summaries are automatically generated weekly using AI based on recent user reviews. Firefox Browser Add-ons does not verify user reviews, so some user reviews may be inaccurate, spammy, or outdated.
  • Works well and looks nice
  • Does everything right
  • Formatted JSON is not fully visible when too large
  • No support for dark mode
Most mentioned
  • Works well and looks nice
  • Formatted JSON is not fully visible when too large
Recent reviews
by Сергей, 2024-03-30

by Сергей, 2024-03-30

by Сергей, 2024-03-30
View all user reviews
Risk impact

JSON Lite is risky to use as it requires a number of sensitive permissions that can potentially harm your browser and steal your data. Exercise caution when installing this add-on. Review carefully before installing. We recommend that you only install JSON Lite if you trust the publisher.

Risk likelihood

JSON Lite has earned a fairly good reputation and likely can be trusted.

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