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Online 'Timing-Allow-Origin' Checker

This tool tests whether a page can use the Resource Timing API to gather performance information from third party domains and CDNs. The Resource Timing API gives visibility into how files and resources are impacting a site’s performance.

Online 'Timing-Allow-Origin' Checker

Test For HTTP Timing Allow Origin Headers

Enter the URL of any image, script, font, or other file to see whether your CDN or third party domain is returning a properly configured timing-allow-origin header. The timing-allow-origin header allows the Resource Timing API to gather performance timing information from 3rd party domains, which gives more insight into page performance.

Enter a URL to get started!