ScreenSync — Responsive Preview
Extension Actions
See your website on multiple screen sizes simultaneously. Live, side by side, as you code.
ScreenSync lets frontend developers preview their website on mobile, tablet, laptop, and desktop viewports simultaneously in a single Chrome tab.
Stop toggling Chrome DevTools device toolbar one screen size at a time. With ScreenSync, you see all sizes at once.
HOW IT WORKS
1. Open any website or localhost page
2. Click the ScreenSync icon
3. Select your viewports (Mobile, Tablet, Laptop, Desktop)
4. Hit Launch
5. See your site at all sizes in one view
FEATURES
4 preset viewports: Mobile (375px), Tablet (768px), Laptop (1024px), Desktop (1440px)
Custom viewport sizes: Add any width and height you need
Synced scrolling: Scroll one viewport and all others follow proportionally
Auto refresh mode: Automatically reloads all viewports every 2 seconds
Zoom controls: Zoom in, zoom out, fit to screen
Keyboard shortcuts: Press + to zoom in, 0 to reset, R to refresh all
Works with localhost and any URL
Lightweight: No separate app to download, works right in Chrome
PERFECT FOR
Frontend developers testing responsive designs
Freelancers building client websites
Teams reviewing layouts across breakpoints
Anyone who writes CSS and needs to check multiple screen sizes
WHY NOT JUST USE DEVTOOLS?
Chrome DevTools only shows one screen size at a time. You have to toggle back and forth, checking each size individually. ScreenSync shows all sizes simultaneously so you catch responsive bugs the moment you write the CSS.
NO DATA COLLECTION
ScreenSync does not collect, store, or transmit any user data. It works entirely within your browser.