Front-end engineers
Verify breakpoints against the live DOM at true device widths, with no DevTools toggle and no window gymnastics.
NewWorkspace boards - 10 devices at once
Your website, flawlesson every iPhone.
Viewport overlays true-to-spec device frames on the site you are already viewing. Compare breakpoints side by side, catch layout bugs before QA does, and export framed screenshots or 4K recordings - entirely on your own machine.
Any site · 38 devices · Settings synced across tabs · No account, no telemetry, no upload
Chrome Web Store★ 5.0·5,000+ users
FeaturedRecommended by Chrome
yourstore.com
Who it is for
One extension, three workflows
The people who build responsive interfaces, the people who design them, and the people who have to prove they work.
Product designers
Check spacing, type scale and safe areas in accurate frames, then export framed captures straight into a spec or a deck.
Agencies and freelancers
Prove responsive quality live on a call. One screen-share shows desktop and mobile behaving together, with no split windows.
Capabilities
Four things it does absurdly well
No feature soup. These are the four capabilities the whole extension is built around.
Live demo
Drive the extension, right here
This is the real workflow: pick a device from the toolbar, rotate it, fire a screenshot, hit record. The page behind it is your site.
yourpage.com
402 x 874/34%
Viewport
From build to sign-off
Prove it works before anyone asks
Responsive quality is far easier to show than to describe. Viewport turns an internal check into something you can hand straight to a client.
Getting started
Running in three clicks
No config file, no account, no project setup.
01
Open any page
Click the toolbar icon. A device appears over the live site, already loaded and fully interactive.
02
Shape the view
Pick a device, rotate, scale and drag it anywhere - or lay out a whole board of phones, tablets and monitors.
03
Compare and capture
Scroll in lockstep across every frame, then export a framed screenshot or record the entire walkthrough.
Measured, not claimed
Where Viewport pulls ahead
Checked against the most-installed responsive preview extensions on the Chrome Web Store.
| Capability | Viewport | Typical simulator |
|---|---|---|
| Device frames | Vector, every device | Bitmap, a handful |
| Site refuses framing | Real-window fallback | Error message |
| Security headers relaxed | Previewed origin only | Every frame in the tab |
| Tells you it relaxed them | On screen, while active | Buried in the policy |
| MP4 export | Production H.264 | Marked experimental |
| Recording resolution | Up to 4K, adaptive | 1080p |
| Client hints match the UA | Always | Contradictory |
| Network throttling | 3G / 4G / offline | - |
| Touch-target and contrast audit | Built in | - |
| Sends data anywhere | Never | Varies |
Local-first architecture
Nothing leaves your machine - and we show our work
Viewport has no backend for your data. No analytics, no telemetry, no remotely-loaded code. Settings live in chrome.storage.local; captures download straight to your disk.
To render a page inside a frame, browsers require us to relax X-Frame-Options and Content-Security-Policy on the preview request. We scope that to the previewed origin alone - third-party frames on the page keep their protections - and show a banner while it is active. It is removed the moment you close the preview.
Most tools do this silently, and tab-wide. We would rather you knew.
Pricing
Free forever. Pro when the work demands it.
The free tier is a working tool with no time limit, not a trial.
Free
$0forever
- All 38 device frames
- Up to 3 devices on screen
- Unlimited framed screenshots
- 2-minute WebM capture
- Real-window fallback on strict sites
Pro
Most popular$4.17/ month, $50 billed yearly
- Everything in Free, plus:
- 10-device boards and saved scenes
- Unlimited 4K MP4, trim and speed
- Build comparison and layout audits
- Network throttling, geolocation, locale
14-day Pro trialCancel anytimeSecure checkout by Lemon Squeezy
FAQ
Answers, before you ask
The five questions every developer asks before installing.
No - nothing that runs inside a browser does. Viewport renders your real page at true device viewport widths with matching client hints, which catches the overwhelming majority of layout and breakpoint problems. Release-critical checks still belong on real devices.
Stop shipping breakpoints you never saw.
Add Viewport to Chrome and check every device on the page you are already looking at. Free, no account, nothing uploaded.