The Device Toolbar opens in Responsive Viewport Mode. The webpage is rendered within the Device Emulation pane. Or, in DevTools, select Customize and control DevTools (. In the Activity Bar, click the Toggle device emulation ( ) button. For example, right-click in a webpage and then select Inspect. To open the UI that enables you to simulate a mobile viewport: Your machine can be a notebook or desktop computer. You can view, change, debug, profile, or all four while you interact with the code. Use Remote Debugging to interact with the code of a page from your machine while your page actually runs on a mobile device. For the most robust testing, run your page on a mobile device. For example, the architecture of mobile CPUs is different than the architecture of laptop or desktop CPUs. Some aspects of mobile devices aren't emulated in DevTools. Instead, you simulate the mobile user experience from your laptop or desktop. Device Emulation doesn't actually run your code on a mobile device.
Use the Device Emulation tool, sometimes called Device Mode, to approximate how your page looks and behaves on a mobile device.
