Skip to main content

Comparing Test Results

Comparing test results can be useful to:

  • Investigate what caused a page speed regression
  • See how fast your page is today compared to a month ago
  • Compare a result on a staging site to production
  • Visualize your own page speed next to your competition

Enabling compare mode

  1. Click on a page on the project dashboard to see the page details view
  2. Click the Compare toggle in the top right corner.

Compare mode toggle for a test result

After enabling compare mode the line charts will show up as bar charts showing just the current select result and the previous result.

For example, in this case we've selected the date where a performance regression was introduced and can then compare the before and after data.

Charts in compare mode

When compare mode is enabled, DebugBear shows result data for both tests side by side or one below the other. The video view shows the previous fast result on the left and the new slower result on the right.

Video view in compare mode

You can also click on an the name of a metric to see why that metric has changed. In this example we can see that a new render-blocking script was introduced and the page now takes longer to start rendering.

Comparative FCP and waterfall

Comparing test results across different pages

To compare results between two pages you can:

  1. Open the test result dropdown
  2. Click Compare to another test result

Test result dropdown

  1. Finally, select the page and test date you want to compare to

Selection UI for the other test

Changing the results that are included in the comparison

Once you've entered compare mode you can also click the gear icon to change the selected test result.

View of selected tests and gear dropdown for changing it