Request Metrics Resource Performance Monitoring

Introducing Resource Performance Monitoring

Discover the resources that slow down your website

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!