Smartphone Side Panel – Mobile View Simulator & Synced Scrolling

Shows the current page as an iPhone/Android-style mobile view in the side panel, with two-way sync of navigation, scroll and forms.

Smartphone Side Panel is a Chrome extension that shows a mobile view of the page you're browsing right next to it, at any time. One click on the toolbar icon opens the mobile view in Chrome's side panel, inside an iPhone- or Android-style device frame. The desktop view and the mobile view stay in sync both ways: scrolling, navigation and form input. Check responsive design and mobile support as part of your normal browsing, without setting up real devices or emulators and without opening DevTools every time. It works right after installation, with no complicated setup. ■ Who it's for • Web designers, UI/UX designers, front-end developers and coders • QA and test engineers, web directors and product managers • Agencies and freelancers presenting and demoing sites to clients • Anyone who wants to see how a blog, online store or CMS article looks on a phone • Marketers checking landing pages and the destinations of ads and newsletters on mobile • People checking SEO and mobile-friendliness, and customer support teams • Students learning responsive design and the instructors who teach it ■ What you can use it for • Checking media queries and breakpoints, and catching layout issues early • Design reviews, final checks before release, and checking staging environments • Reproducing mobile bugs reported by users • Researching the mobile versions of competitor and reference sites • Presentations and meetings where you show the desktop and mobile versions at the same time ■ Main features [Desktop and mobile side by side, whenever you need it] • One click on the icon opens the mobile view in the side panel. You can also use a keyboard shortcut (Alt+Shift+M by default) • The mobile view stays open as you move between pages or switch tabs, and automatically follows the page you're looking at • Your desktop tab keeps working as usual, so you can check while you browse. No more jumping between tabs and windows • You can choose whether the side panel appears on the left or the right in Chrome settings [Two-way scroll sync] • Scroll either the desktop view or the mobile view, and the other one follows to the same content • Positions are aligned using common elements such as headings and images, so the views stay matched even when the desktop and mobile pages have different lengths and layouts • Hold Alt while scrolling to move only one side for a moment [Navigation, reloads and form input stay in sync too] • Open a link on either side and the other side goes to the same page. Back and forward work as well • When the desktop page reloads (including reloads triggered by other extensions), the mobile view reloads too • Input in text fields, text areas, select boxes, checkboxes and radio buttons is mirrored to the other side, so you can check contact and search forms in one go (passwords and credit card details are never synced) [A mobile view that behaves like a real phone] • The same URL is loaded as the browser of the device you choose (Safari on iPhone, Chrome on Android) • Sites that switch layouts based on the User-Agent or Client Hints, and sites that detect the device with JavaScript, show their mobile versions • Each device is shown at its real screen size in CSS pixels, and values such as touch support match the device • Sites you're signed in to stay signed in, so you can check them in the mobile view • In most cases, pages that are set to refuse being shown in an iframe can still be displayed [Touch, recreated with your mouse] • Inside the mobile view, the cursor turns into a round dot like a fingertip • Drag with the mouse to scroll, and the page keeps gliding with momentum when you let go • Swipe carousels and sliders with the mouse (scroll snapping is supported) • Clicks are treated as taps, and the page receives touch events • Scrolling with the mouse wheel still works, and you can switch back to normal mouse input at any time [Devices and display options] • iPhone screen sizes • Android screen sizes • Switch devices instantly from the toolbar • Device frames with Dynamic Island, notch, home button or punch-hole camera, plus a status bar with the time, signal and battery • Portrait and landscape • A frameless mode that shows a tall view filling the full height of the panel • Automatic fit to the panel width, or actual size • The status bar color follows the page's theme color • The panel supports light and dark mode [For sites under development] • Pages on localhost, development servers and staging environments can be shown too • With a development server that supports hot reload, changes appear in both the desktop and the mobile view ■ Privacy and safety • The extension never collects or sends your browsing history, page content or form input. Everything happens inside your browser • You choose between "Allow on this site" and "Allow on all sites" for site access, and you can revoke it at any time • Network requests are modified only for the mobile view in the side panel, and only while the side panel is open. Requests from your normal tabs are never changed • Free, with no ads and no account required ■ How to use 1. Open the page you want to check on mobile and click the icon in the toolbar 2. The first time, allow access to the site 3. Use the toolbar to switch the device, orientation and display mode, and to turn scroll, navigation and form sync on or off ■ Languages Available in 55 languages, including English and Japanese. ■ Please note • The mobile view is a simulation that uses Chrome's rendering engine. It doesn't run iOS or Android itself and doesn't reproduce Safari-specific rendering differences, so we recommend a final check on a real device before release • CSS hover detection, screen resolution (devicePixelRatio) and pinch-to-zoom are not reproduced • Some pages can't be shown in the mobile view, for example sites that block embedding with JavaScript • It doesn't work on Chrome's internal pages, such as the settings page, or on the Chrome Web Store