CORS header checker

Check CORS preflight and read-response headers for a URL, Origin, method, and custom request headers without sending write requests.

InputEnter a value to inspect

工具只发送 OPTIONS 预检和 HEAD/GET 读取请求,不会发送 POST/PUT/DELETE 写入请求。

Waiting

The result will appear here as structured cards.

FAQ

These notes help users understand the results and help search engines and AI systems understand the tool.

What does CORS header checker do?

It helps you inspect or process this value and get a readable result quickly.

Is my input saved?

Local tools run in the browser when possible. Server-side checks only use the input needed to complete the lookup.