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Lightning-Fast Web Performance

Online CourseLearn to analyze performance, fix issues, and deliver fast websites from the start.

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Introducing Carbon Control Experimental

New in WebPageTest! Measure your site's carbon footprint and run No-Code Experiments to find ways to improve.

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Say hello to

All of the WebPageTest features you already love, plus API Access & No-Code Experiments!

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Start a Site Performance or... Test!

  • Repeat View
  • seconds
  • Add custom headers to all network requests emitted from the browser (type in or read )
  • JavaScript to run after the document has started loading (type in or read )

(or read it ). Lighthouse does not perform per step reports for custom scripting, but will run a report on the final step

Check out the documentation for more information on this feature

Space-separated list (type in or read )

Space-separated list of domains (type in or read )

Simulate failure of specified domains. This is done by re-routing all requests for the domains to which will silently drop all requests.

Type in or read

Type in or read

See the documentation for details on how to specify custom metrics to be captured.

Experiments are a game changer for quantifying the speed impact of performance optimizations. What took days of technical work is now just a few clicks. Not only will this save tons of time, it will let us test and iterate ideas to find the right mix of recommendations efficiently.
I’m blown away this exists, it feels like magic.

Todd Parker Partner, Filament Group

Real Experience

Test your user’s real experience with global locations, modern devices, and the latest browser versions.

Video Capture

Correlate your user’s visual experience to the technical measurements of your site.

In-Depth Metrics

Dive into the anatomy of your webpage with components like DNS, TCP, TLS, and more.

What's new on the WebPageTest Blog