Responsive Lens – Responsive Viewer & Screen Size Tester

See any website on 90 real phones, tablets and computers, right over the page. Compare devices, take mockups and record video.

See your website on any phone, tablet or laptop, without leaving the page. Responsive Lens is a free responsive design tester for Chrome. Click the toolbar button on any site and it opens inside a lifelike device frame with a working browser bar. Links work, and the page gets the device's screen size, user agent, touch support and pixel density, so mobile menus and touch layouts behave as they would on a real phone. No sign-up. No ads. No tracking. Every feature is free. ★ 90 DEVICES, UP TO DATE FOR 2026 • Current and older iPhones and Android phones • Foldable phones, in both folded and open positions • Tablets, smartwatches, laptops and desktop screens from HD to QHD • Special screens such as a Smart TV, a kiosk and a rugged scanner • Add your own custom screen sizes ★ COMPARE SCREEN SIZES SIDE BY SIDE Put up to four devices next to each other. Scroll, tap, type or follow a link in one and the others follow, so you can check a whole sign-up or checkout flow on every screen in one pass. ★ FEELS LIKE A PHONE • Drag to scroll with your mouse, with momentum, like a finger • A phone keyboard slides up when you type in a form • Rotate to landscape and zoom from 50% to 125% • A live status bar and each phone's camera cutout ★ SCREENSHOTS, MOCKUPS AND VIDEO • Save a screenshot of the screen, or a mockup inside the device frame on a transparent background • Put several devices on one image • Record a video of the devices as you click through your site ★ FIND RESPONSIVE BUGS FAST • Breakpoint view: one pane per CSS media query breakpoint, read from your stylesheets or from common framework presets • Fluid mode: drag to any width while a ruler marks your breakpoints • Overflow finder: names and outlines the elements that make the page scroll sideways • Outline layout, hide scrollbars, and preview light or dark mode • Device info: viewport size, pixel ratio and user agent, with one-click copy ★ WORKS WITH YOUR LOCAL SITE Test live websites and local development servers, so you can check your design while you build it. HOW TO USE 1. Pin Responsive Lens to your Chrome toolbar. 2. Open any website and click the icon, or press Alt+Shift+R. 3. Pick a device from the grid. Press Esc to close. PRIVACY No account, no analytics, no tracking. The sites you test, your screenshots and your recordings never leave your computer.