The most popular and feature rich CORS tool on Chrome (over 100K weekly active users) is rebuilt for Firefox with more features.
This plugin allows you to send cross-domain requests. You can also override Request Origin and CORS headers.

Moesif Origin & CORS Changer - A Firefox Add-On for Cross-Domain Requests
Moesif Origin & CORS Changer is a versatile Firefox add-on widely used by developers. It enables sending of cross-domain requests, overriding of Request Origin and CORS headers. It’s a Firefox adaptation of the widely popular Chrome extension and also allows selective enabling for white-listed domains, adding incredible utility to your browser for managing cross-origin resource sharing (CORS).
Add-on stats
Manifest V2
Weekly download count: 39
Firefox on Android: No
Permissions:
- webRequest
- <all_urls>
- webRequestBlocking
Size: 469.88K
Email: su*****@moesif.com
URLs: Website
Full description: See detailed description
Ranking
Other platforms
Not available on Chrome
Not available on Android
Not available on Edge
User reviews
Pros
- Customizable for fixing cross-origin sharing issues
- Easy to use
- Good functionality as a CORS extension
Cons
- Requires email to unlock advanced settings
- Concerns over privacy with email requirement
- Support issues on certain Firefox versions
Most mentioned
- Email requirement to unlock settings
- Customization options
- Functionality for CORS
User reviews
by JoaCHIP, 2025-02-20
by 退出中共邪教党团队避疫, 2025-02-13
I agree with other recent reviewers. The screenshot shows a lot of fields, but none of them are enabled unless I "Unlock Advanced Settings" (which are in fact any settings) by providing my email. I know I could use a burner email for that, but meh, whatever. Cheers, bye.
by Rimas Kudelis, 2024-03-27
Add-on safety
Risk impact
Moesif Origin & CORS Changer requires some sensitive permissions that could impact your browser and data security. Exercise caution before installing.
Risk impact analysis details
- Critical Grants access to browser tabs, which can be used to track user browsing habits and history, presenting a privacy concern.
- Critical ****** ****** ** *** ********* ****** * *********** ******** **** ** ** *** ******* *** ****** **** **** *** ******* *****
- Low ******* ****** ** *** ********* ********
Risk likelihood
Moesif Origin & CORS Changer has earned a fairly good reputation and likely can be trusted.
Risk likelihood analysis details
- High This extension has low user count. Unpopular extensions may not be stable or safe.
- Low **** ********* *** ******* **** **** * ****** **** ***** ******** *** **** ****** ** ** ****** *** *****
- Low **** ********* *** ***** **** **** * ****** **** ***** ********** *** **** ****** ** ** ****** *** *****
- Good **** ********* *** **** **** *******
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