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
Latest, 15 Oct 2026:200,000 usersMove the mouse over the chart for any month
Ratings count
monthly, 3 years
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
Window
Users
Change
Ratings
Rating
7 days
0
+0.0%
0
−0.01
30 days
0
+0.0%
0
−0.01
6 months
0
+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