Measure Speed up

The extent of speed up PageSpeed Service provides depends on a variety of factors such as content on your pages, browser, geographic location of access, bandwidth, etc. This page lists instructions to schedule tests from different locations around the world, on different browsers and on different networks, so you can measure the exact speed up for your site, and understand the results.

Running the tests

  1. Go to http://www.webpagetest.org/compare
  2. Enter the URL of your website, say www.example.com.
    • Optional steps:
    • Choose the test location and browser. The default is IE8 from US East (Virginia).
    • Select More Configurations... for a broader selection of locations, browsers and network connection type. The default connection type is DSL.
  3. Click the Start Test button.

The test may take several minutes to complete, depending on the load on the test servers. The page will automatically refresh every 30 seconds and display the results when it is complete.

Understanding the results

The test involves rendering your website on the selected browser by directly visiting your site, and repeating the same test by proxying your site through PageSpeed Service.

A sample test result is shown below for illustration. The numbers in the Original column indicate the load time for the page when accessing your site directly. The numbers in the Optimized column indicate the load time for the page when your site is proxied through PageSpeed Service. The Difference column indicates the difference in load time between the two test runs. The speed up values are shown as a percentage value in green if PageSpeed Service speeds up your site. The percentage values are shown in red if PageSpeed Service slows down your site. A slow down can happen due to various reasons such as, the default configuration not being optimal for your site. Dynamically changing content on your page can result in the original and optimized test runs not being comparable due to differing number of requests and response sizes. In such cases, please try running the tests on other pages that are comparable or visit this page later. We are constantly working to improve the service.

In the test below, PageSpeed Service loads the site 26.9% faster for the first view, and 62.1% faster for repeat views of the same page. You can click on the Play button (shown as a triangle) under Visual Comparison to view how the page would appear to load to an end user, with and without PageSpeed Service.

Original Optimized Difference
Page Load Time 1.715s 1.253s -0.462s (26.9%)
Repeat View Page Load Time 1.445s 0.547s -0.898s (62.1%)
Full Test Result
view test

view test

Visual Comparison

Performance improvements as reported by webpagetest.org

You can click on the view test link in each column to see more details about the test run. The PageSpeed Score and grades for the test run are shown at the right top corner of the page. You can click on the First View and Repeat View links to find out more details on exactly how PageSpeed Service improved the loading of your page.

Detailed test results for the original web page

webpagetest comparison

Detailed test results for the optimized web page

webpagetest comparison