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Test. Optimize. Repeat!

Instantly test your site’s performance in real browsers, devices, and locations around the world.

screenshot of wpt results page

Start a Site Performance or...

Core Web Vitals
Lighthouse
Visual Comparison
Traceroute

Test!

Enter URL to test

Simple Configuration (Choose from quick recommended test location and browser presets)

Mobile (3 runs) 4G Virginia, USA Desktop (3 runs) Cable Virginia, USA Mobile (3 runs) 3G Mumbai, IndiaDesktop (3 runs) Cable Toronto, CanadaDesktop (3 runs) Cable Frankfurt, Germany

Include Repeat View (Loads the page, closes the browser and then loads the page again)

Run Lighthouse Audit (Runs on Chrome, emulated Moto G4 device, over simulated 3G Fast connection)

Advanced Configuration (Choose from all browser, location, & device options)

Test Location

Browser 0 Pending Tests

Connection

BW Down	BW Up	Latency	Packet Loss
Kbps	Kbps	ms	%

Desktop Browser Dimensions
Number of Tests to Run
Up to 9
Repeat View First View and Repeat View First View Only
Capture Video
Label

Stop Test at Document Complete
Typically, tests run until all activity stops.
Ignore SSL Certificate Errors
e.g. Name mismatch, Self-signed certificates, etc.
Capture network packet trace (tcpdump)
Save response bodies
For text resources (HTML, CSS, etc.)
Preserve original User Agent string
Do not add PTST to the browser UA string
User Agent String
(Custom UA String)
Append to UA String
Disable AVIF image support
Firefox and Chromium-based browsers only
Disable WEBP image support
Firefox and Chromium-based browsers only
Disable JPEG XL image support
Firefox and Chromium-based browsers only
Capture Full Size Video
Enables full size screenshots in the filmstrip
Minimum test duration
Capture data for at least... seconds
Custom headers
Add custom headers to all network requests emitted from the browser
Inject Script
JavaScript to run after the document has started loading

Chrome-specific advanced settings:

Capture Lighthouse Report (Uses a "3G Fast" connection independent of test settings)
Emulate Mobile Browser
Capture Dev Tools Timeline
Enable v8 Sampling Profiler (much larger traces)
Capture V8 Runtime Call Stats
Capture Chrome Trace (about://tracing)
Trace Categories
(when tracing is enabled)
Capture Network Log
Enable Data Reduction
Chrome 34+ on Android
Use Chrome dev tools traffic-shaping (not recommended)
Host Resolver Rules
i.e. MAP * 1.2.3.4
Command-line
Custom options

Enter Script

Script includes sensitive data
The script will be discarded and the HTTP headers will not be available in the results
Discard all HTTP headers

Check out the documentation for more information on this feature

Block Requests Containing (URL substrings)...
Space-separated list

Block Domains (full host names)...
Space-separated list of domains

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

Hosts to fail (one host per line)...

Custom Metrics:

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

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.

“One of the cool features of WebPageTest is that it can generate a filmstrip of screen snapshots taken during a web page load, enabling us to quantify how a page loads, visually. This view makes it significantly easier to determine how long the page is blank for, and how long it takes for the most important content to render.
Being able to look at the results in this way, provides the ability to empathise with the user.”

Andrew Galloni Engineering Director at Cloudflare

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