
Firefox and Chrome browsers have offered developer tools since they were first released.
As more and more web traffic moves to mobile devices, however, we thought it was a good time for a refresher on how to use these multi-device testing tools to test the responsiveness of your site before it goes live.
Your New BFFs for Multi-Device Testing
Firefox
In Firefox, the Responsive Mode tool allows you to either choose from a set of common devices or enter your own dimensions to match your particular device or screen size.
And there are some other nifty perks:
- You can rotate the screen using the tiny icon in the top right corner of the device simulator.
- You can even choose the type of connection your device has—from a slow, regular 2G connection to a fast Wi-Fi connection—which can help you determine load times for your site for your average users.
- Firefox has also added a one-touch screenshot of your view, which you can activate by clicking the little camera icon in the toolbar.

Google Chrome
Chrome has a set of similar features in their Device Toolbar, which is part of their developer suite.
- You can select from a set of predetermined devices, customizing for the devices you want to see or entering custom dimensions.
- Rotating the screen is easy with the rotate icon.
- You have fewer connection simulations on Chrome, but you can still take a screenshot of the device by accessing the auxiliary menu (the three dots).

Why We Love These Free Simulators
We like these free device simulators for a number of reasons:
- Both simulators offer you a better view of your site on various screens sizes than just resizing the browser window.
- They can also help with troubleshooting unusual site issues seen by users of mobile devices.
- Your actual browser dimensions stay the same, so when switching to other tabs, they remain unchanged.
- The presets for various device dimensions are super duper handy.
- The rotate button to switch between portrait and landscape orientations is snappy and a great timesaver.
While nothing can match the experience of viewing your website on an actual, hand-held mobile device, these free tools can make creating a fully responsive website that works on any device much easier.
Featured image credit: Pexels; Firefox and Chrome screenshots: CodeGeek