CORS Unblock icon

CORS Unblock

by balvin.perrie · Developer Tools
Manifest V3 Free
View in Chrome Web Store Data as of 15 Oct 2026

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

Users
200K
0 in 30 days
Rating
4.1 / 5
−0.01 in 30 days
Ratings
175
0 in 30 days
Store rank
#1,300
#1,173 among extensions
Version
0.5.2
updated 3 Jun 2025

Users

monthly, 3 years
30K115K200KAug 2023Apr 2025Oct 2026
Latest, 15 Oct 2026: 200,000 usersMove the mouse over the chart for any month

Ratings count

monthly, 3 years
30103176Aug 2023Apr 2025Oct 2026
Latest, 15 Oct 2026: 175 ratingsMove the mouse over the chart for any month

The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.

About CORS Unblock

This extension bypasses the "XMLHttpRequest" and "fetch" rejections by altering the "Access-Control-Allow-Origin" and "Access-Control-Allow-Methods" headers for every request that the browser receives. You can activate the extension by pressing the action button. Also, use the right-click context menu over the action button to modify which headers the extension manipulates. You can also ask the extension not to overwrite these headers when the server returns values for them. The default values for the headers: Access-Control-Allow-Origin: request initiator or empty Access-Control-Allow-Methods": GET, PUT, POST, DELETE, HEAD, OPTIONS, PATCH, PROPFIND, PROPPATCH, MKCOL, COPY, MOVE, LOCK Access-Control-Allow-Methods: request initiator or empty Access-Control-Allow-Credentials: true Access-Control-Expose-Headers: request initiator or * Additional Features: 1. It can remove the following CSP-related headers: "Content-Security-Policy", "Content-Security-Policy-Report-Only", "X-WebKit-CSP" and "X-Content-Security-Policy". 2. It can overwrite the returned 4xx status code from the server. Use this feature when a server does not support a method, but you want to pretend it does. 3. It can append necessary headers to pretend websites (local or remote hosts) support SharedArrayBuffer class. 4. It can permit cross-origin frame embedding (by removing the "X-Frame-Options" header) to simplify remote page embedding during local development. 5. It can include or exclude the "referer" and "origin" headers when a server is sensitive to them to work appropriately. 6. The extension optionally uses the "chrome.debugger" to overwrite 4xx status codes (in case a server does not support a method, you can use this feature to pretend the server accepts a response or supports an unsupported method). 7. The extension also optionally fixes CORS policies of redirected URLs. -- It is important to note that this extension fixes preflight requests to permit access to any custom header (when enabled). Links: 1. For reporting bugs, please use the link https://github.com/balvin-perrie/Access-Control-Allow-Origin---Unblock. 2. To have better control over CSP (content-security-policy), try my https://chrome.google.com/webstore/detail/csp-unblock/lkbelpgpclajeekijigjffllhigbhobd.

Growth

WindowUsersChangeRatingsRating
7 days0+0.0%0−0.01
30 days0+0.0%0−0.01
6 months0+0.0%−1−0.02
1 year+100K+100.0%+1−0.03

Chrome Web Store search rankings

Where CORS Unblock appears when people search the store, with the 30 day change
Search phrasePosition30 days
unblock#60
policy#12+1
request#64+3
options#70new

Version history

17 versions recorded
0.5.23 Jun 2025
0.5.11 May 2025
0.5.020 Apr 2025
0.3.811 Feb 2024
0.3.721 Aug 2023
0.3.615 Jan 2023
0.3.54 Dec 2022
0.3.426 Apr 2022

Details

Category
Developer Tools
First seen
27 May 2020
Size
198 KB
Languages
en
Pricing
Free
Privacy policy
add0n.com
Support
webextension.org
Extension ID
lfhmikememgdcahcdlaciloancbhjino

Permissions and risk

Moderate riskimpact 3, likelihood 1
Permissions
storagedeclarativeNetRequestdebugger
Site access
<all_urls>
Can read and change data on every website you visit.

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