Throttling

Sofia Emelianova
Sofia Emelianova

In Settings. Settings > Throttling, you can:

  • Calibrate CPU throttling presets to approximate the typical performance of low- and mid-tier mobile devices.
  • Set up custom throttling profiles. You can use these profiles to test custom connection speeds in the Network panel.

The Throttling tab.

Calibrate CPU throttling presets

To calibrate CPU throttling presets:

  1. Open Settings.
  2. In the Throttling > CPU throttling presets, click Calibrate and Continue.
  3. Wait about 5 seconds for DevTools to navigate away from your current page and reload it.

The Throttling tab will show the CPU throttling rates that you can apply to your device to get an idea of how your page performs on low- and mid-tier mobile devices.

Calibrated rates next for low- and mid-tier mobile devices.

With presets calibrated, you can find them in Performance > Environment settings > CPU and in Performance > Capture settings drop-down menus.

Calibrated rates next in drop-down menus in the Performance panel.

Set up custom network throttling profile

To add a custom network throttling profile:

  1. Open Settings.
  2. In Throttling > Network throttling profiles, click Add profile.
  3. Specify the following optional parameter values for the new entry:

    Creating a new profile in the Throttling tab.

    • Profile Name.
    • Download and Upload speeds in Kbps.
    • Latency in milliseconds.

    Packed-related parameters:

    • Packer loss in percent.
    • Packet queue length as a number.
    • Packet reordering flag, on or off.
  4. Click Add to save the new profile. You can now select it from the throttling drop-down list in the Network panel.

To edit or remove an existing profile, click Edit. or Delete. buttons that appear on hover.