Responsive Device Viewer & Mobile Tester

Responsive website tester for mobile, tablet, desktop, and laptop previews with screenshots, mockups, and annotations.

Multi Device Viewer is a responsive testing and mobile preview extension for checking how websites look across phones, tablets, laptops, desktops, watches, and TVs. Open the extension on any page to compare multiple device viewports side by side without leaving the site. Click the extension icon or use the Chrome context menu, and the current site immediately appears inside realistic device frames without navigating away or opening a new tab. Close the overlay and the page is exactly as you left it. Responsive Website Testing - Compare up to four device viewports side by side in resizable panels. - Choose from a built-in catalog of phones, tablets, laptops, desktops, watches, and TVs, including newer iPhone profiles. - Switch orientation, zoom, fit mode, and reload each panel independently. - Use the global URL bar to send a page to every active preview. - Save favorites, browse recents, or create a custom viewport size. - Turn on dark mode or inspect mode for focused responsive QA. Mobile, Tablet, Desktop, and Laptop Preview - Test mobile view, tablet layouts, laptop breakpoints, desktop screens, watch layouts, and TV previews in one workspace. - Use realistic device shells for phone, tablet, laptop, desktop, and watch previews. - Move quickly between common responsive design breakpoints and exact custom viewport sizes. Presets for repeat QA - Start from built-in layouts like Mobile vs Tablet, iOS vs Android, and Android + Tablet + Laptop. - Save your own named device layouts. - Import or export preset JSON for reuse across local browser profiles. Screenshots, Mockups, and Annotations - One click in the sidebar captures the entire simulator view as-is. - Built-in annotation editor: pen, rectangle, arrow, text, and crop tools. - Eight-color palette, three stroke widths, font size picker. - Crop bakes your annotations into a trimmed canvas. - Copy to clipboard or download — everything stays on your machine. Privacy-first by design - No account required. - No backend service. - No analytics, telemetry, or remote logging. - Screenshots, URLs, annotations, and settings never leave your browser. - Preferences, presets, recents, custom devices, and UI state are saved locally in Chrome storage.