Creating A Clean Testing Environment

A clean testing environment allows you to to easily determine the point of failure for your site or web application, rather than wondering if it was something in the background that caused your slow-down or failure.

Apps, extensions, background processes and unnecessary tabs are only some of the things that can impact your profiling figures and should be avoided where possible. This is of particular relevance when you wish to accurately profile using the Timeline, Profiles or about:tracing.

To set up a clean testing environment:
  • Ensure Chrome is being run with a clean profile:
    • Option 1: Use Incognito mode. Open the Chrome menu Chrome menu and select New Incognito Window, or launch Chrome with the --incognito switch.

    • Option 2: Use a fresh Chrome profile. Click the user icon in the top-right corner of your Chrome window and select New User.


      To guarantee a clean profile doesn't inherit any extensions or settings, launch Chrome using the --user-data-dir switch with the path '/dev/null'. e.g:

      • OSX: open -a "Google Chrome" --args --user-data-dir=/dev/null
      • Linux: google-chrome --user-data-dir=/dev/null
      • Windows: "C:\Users\username\AppData\Local\Google\Chrome\Application\chrome.exe" --user-data-dir=/dev/null

      Launching Chrome like this will ensure you get a completely empty profile instead of loading the user's profile as read-only.

    • Close other tabs and processes/applications that may be running in the background. If these apps need to run in the background, use your system monitor to ensure apps are not utilizing too much CPU or RAM.
    • Disable any Dynamic CPU overclocking that may be enabled on your system.
    • Make sure you are up-to-date with the latest build of Chrome. You can use to grab an edge build.
    • If you are running into a bug and generally use Chrome Canary as your development browser, it is worth testing in Chrome Stable to ensure the issue is unrelated to new features or bugs.