CORS Unblock

No more CORS error by appending 'Access-Control-Allow-Origin: *' header to local and remote web requests when enabled

CORS Unblock - Eliminate CORS Errors in Firefox

"CORS Unblock" is a Firefox extension offering control over XMLHttpRequest and fetch methods. It appends custom 'access-control-allow-origin' and 'access-control-allow-methods' headers to every browser request, resolving CORS (Cross Origin Resource Sharing) errors. Its features include toggling on/off from the toolbar, customizing allowed methods, and options to not overwrite server-filled headers. Supports WEBDAV methods.

Add-on stats

By: Balvin
Users: 7,081
597
Rating: 3.90
(29)
Version: 0.3.8 (Last updated: 2024-02-11)
Creation date: 2019-01-22
Weekly download count: 378
Firefox on Android: No
Risk impact: High risk impact
Risk likelihood:
Manifest version: 2
Permissions:
  • storage
  • <all_urls>
  • webRequest
  • webRequestBlocking
  • declarativeNetRequest
  • contextMenus
Size: 211.30K
URLs: Website

Other platforms

CORS Unblock (v0.3.8)
4.16 (162) 200,000
Not available on Android
CORS Unblock (v0.3.8)
4.30 (12) 52,552
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Add-on summary

This extension provides control over XMLHttpRequest and fetch methods by providing custom "access-control-allow-origin" and "access-control-allow-methods" headers to every requests that the browser receives. A user can toggle the extension on and off from the toolbar button. To modify how these headers are altered, use the right-click context menu items. You can customize what method are allowed. The default option is to allow 'GET', 'PUT', 'POST', 'DELETE', 'HEAD', 'OPTIONS', 'PATCH' methods. You can also ask the extension not to overwrite these headers when the server already fills them.

Preview: https://www.youtube.com/watch?v=8berLeTjKDM

Default values: Access-Control-Allow-Origin: request initiator or '' Access-Control-Allow-Methods: 'GET, PUT, POST, DELETE, HEAD, OPTIONS, PATCH, PROPFIND, PROPPATCH, MKCOL, COPY, MOVE, LOCK' Access-Control-Allow-Methods: request initiator or '' Access-Control-Allow-Credentials: 'true' Access-Control-Expose-Headers: request initiator or '*'

To report bugs please use: https://github.com/balvin-perrie/Access-Control-Allow-Origin---Unblock

Change Log:

See more

User reviews

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.
Pros
  • Works as expected for some users
  • Useful for frontend developers
  • Ability to modify 'Access-Control-Expose-Headers'
Cons
  • Does not work for multiple versions of Firefox
  • Inconsistent performance on certain sites
  • Lack of a whitelisting option for specific sites
Most mentioned
  • Does not work
  • Whitelist option is desired
  • Works well for some users
User reviews
by waldyrious, 2024-12-28

Does what it says on the tin, would be nice though to have the ability to whitelist sites, like just localhost, instead of all domains.
by Zach Bellay, 2024-11-05

Great that you can modify "Access-Control-Expose-Headers", too! Very useful.
by tvogel, 2024-06-20
View all user reviews

Add-on safety

Risk impact

CORS Unblock requires some sensitive permissions that could impact your browser and data security. Exercise caution before installing.

Risk likelihood

CORS Unblock has earned a fairly good reputation and likely can be trusted.

Upgrade to see risk analysis details