Check URI accessibility via CORS

No Authorization.
No request was performed.
Please note: bookmarks are saved in localStorage (your browser persistent memory).

This page can be saved and run localy or from some online source.
It performs a window.fetch() request to a remote source.


  • URI protocol can be HTTP as well as HTTPS.
    HTTPS is mandatory when the actual source location is HTTPS.
  • Caching is excluded
  • An authorization can be included
  • Multiple custom request headers can be included
  • Recall last used URI also when changing Method
  • When browser localStorage is available:
    • Recall last Request parameters
    • Bookmarks management

This tool can be useful to check:

  1. URI response status and headers
  2. Total time elapsed for the response
  3. CORS preflight and accessibility

Don't forget that preflight request (method “OPTIONS”) can return a 200 as well a 204 status, but this isn’t enough.
An “Access-Control-Allow-Methods” header is expected, valued with the same method of the request (optionally listed in a comma-separated list of Methods).

© 2023 M. Balestra