Mobile View & Responsive Tester
Add to Chrome
See your page across phones, tablets, laptops, and desktops in one focused workspace. Catch layout issues, compare designs, and hand off fixes—without sending your work to a backend.
TRUST IS A PRODUCT FEATURE
The extension has no account, advertising, telemetry, remote logging, or automatic uploads. URLs, captures, saved sets, design references, and generated prompts stay in your browser unless you choose to export them. The public marketing site does not use analytics or session recording.
Read the plain-language privacy policy →The extension is open source under the MIT license. Review permissions, inspect local storage behavior, report issues, or contribute improvements in the public repository.
Explore the source on GitHub ↗ONE WORKSPACE, THE WHOLE RESPONSIVE LOOP
Everything you need for fast responsive review, without turning the workflow into another platform to manage.
Open up to four resizable previews. Switch devices, rotate, zoom, reorder, focus, and save the combinations you test every day.
Keep matching pages aligned while you check how layout and interactions change across breakpoints.
Place a reference beside or over a live viewport, adjust alignment, and turn visual differences into clear feedback.
Generate a ready-to-copy coding prompt with active viewports, optional issue details, constraints, and verification guidance.
Capture and annotate the workspace or record the source tab so a teammate can reproduce the issue quickly.
Open a LAN-ready development page from a QR code, then validate the critical path on physical hardware before release.
Read the responsive testing guide →A SHORTER FEEDBACK LOOP
Launch from the tab you are already developing, including localhost.
Start from a saved set or build the exact range your users need.
Copy a fix prompt, annotate a capture, or continue on a physical device.
COMMON QUESTIONS
It is a fast responsive development aid inside Chrome or Firefox. It reproduces viewport dimensions and useful device presentation, while final release testing should still cover physical devices and target browsers.
Yes. Open your local development page in Chrome or Firefox, then launch the extension. For physical-device handoff, expose the dev server on your LAN and use your computer's network address instead of localhost.
Some applications prevent embedding through authentication rules or frame protection. The viewer reports the limitation and provides an open-in-tab fallback.
No. It formats a prompt locally for you to copy into the coding assistant of your choice. The extension does not send the prompt or your code to an AI service.
FREE · PRIVATE · OPEN SOURCE
Install the extension and start with the page already open in your browser.