Website Uptime Checker
Check if any website is online or down instantly.
CheckCORS Headers Checker
Inspect public response headers for cross-origin resource sharing declarations.
Live Results
Enter a public target to begin.
About CORS Headers Checker
CORS Headers Checker brings the required input, options and result into one focused workflow. Inspect public response headers for cross-origin resource sharing declarations. The result changes when the source data or selected options change, so it is easy to run a second comparison.
For a typical workflow, use it to run a fresh diagnostic after a hosting, DNS, certificate, redirect, content or performance change. Start with a representative input, inspect the first result, then adjust one setting at a time if you need a different outcome.
The checker uses the public target you enter to make a diagnostic request. Do not place credentials or private access tokens in a URL.
Using CORS Headers Checker well
Input
What to prepare
The public URL, domain, IP address, record type, or audit option requested by the checker.
Result
What the tool returns
A point-in-time observation from the public target and the checks available on this page.
Useful situations
- Investigating a public-site problem with CORS Headers Checker.
- Verifying a recent configuration change with CORS Headers Checker.
- Collecting a diagnostic snapshot before troubleshooting with CORS Headers Checker.
Checks and limitations
- Results can vary by location, cache, DNS propagation and temporary server conditions. Confirm important findings with the relevant host or service.
- Treat the output as a current diagnostic snapshot rather than a permanent guarantee.
Related Website Tools
View All Website Tools →How it works
1. Add the Required Input
The public URL, domain, IP address, record type, or audit option requested by the checker.
2. Review CORS Headers Checker Options
Choose only the settings that apply to the result you need; leave optional controls unchanged when you are unsure.
3. Run a Fresh Check
Start the task and wait for the interface to return its result or a clear setup message.
4. Verify Before You Use It
Results can vary by location, cache, DNS propagation and temporary server conditions. Confirm important findings with the relevant host or service.
Frequently Asked Questions
The public URL, domain, IP address, record type, or audit option requested by the checker. Start with a representative input and use only the options needed for your intended result.
A point-in-time observation from the public target and the checks available on this page. Treat the output as a current diagnostic snapshot rather than a permanent guarantee.
Results can vary by location, cache, DNS propagation and temporary server conditions. Confirm important findings with the relevant host or service.
The checker uses the public target you enter to make a diagnostic request. Do not place credentials or private access tokens in a URL.
The page can be used without creating a visitor account. Your browser or device may limit unusually large files or demanding media jobs.