The fastest visual responsive testing workspace for developers, designers, agencies, and clients.
Users
5
−3 in 30 days
Rating
0.0 / 5
unchanged in 30 days
Ratings
0
0 in 30 days
Store rank
#261K
#218K among extensions
Version
1.0.0
updated 27 Jul 2026
Users
monthly, 3 months
Latest, 16 Oct 2026:5 usersMove the mouse over the chart for any month
Ratings count
monthly, 3 months
Latest, 16 Oct 2026:0 ratingsMove the mouse over the chart for any month
The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.
About ViewPortX - Responsive Testing Workspace
ViewPortX – Responsive Website Testing Made Easy
ViewPortX helps you test responsive websites faster by showing multiple screen sizes in one workspace. Instead of constantly resizing your browser or switching between devices, you can preview your website across mobile, tablet, laptop, and desktop layouts side by side.
Whether you're building a website, checking a new design, or testing updates, ViewPortX makes responsive testing simple and efficient.
Features
View Multiple Devices Together
Preview websites on mobile, tablet, laptop, and desktop screens.
Compare different screen sizes side by side.
Switch between Grid View and Focus View.
Change between portrait and landscape orientation.
Synchronized Scrolling
Scroll one viewport and keep all other viewports in sync.
Test responsive layouts more quickly.
Check how pages behave across different screen sizes.
Device Frames
Display websites inside realistic device frames.
Choose from popular phones, tablets, laptops, desktops, or a simple browser frame.
Create clean previews for clients, presentations, or portfolios.
Custom Screen Sizes
Select from common device presets.
Create your own custom width and height.
Test specific responsive breakpoints for your project.
Screenshots
Capture high-quality screenshots of individual devices or the complete layout.
Save screenshots for design reviews, testing, bug reports, or documentation.
Projects and Workspaces
Save your favorite layouts.
Organize different websites into projects.
Continue your work anytime without setting everything up again.
Who Can Use ViewPortX?
ViewPortX is useful for:
Web Developers testing responsive layouts.
UI/UX Designers reviewing designs on different screen sizes.
QA Engineers checking responsive issues.
Agencies and Freelancers presenting websites to clients.
Fast and Privacy Friendly
Works directly inside your browser.
No server processing required.
No unnecessary data collection.
Fast and lightweight for everyday use.
Getting Started
Install the ViewPortX extension.
Open any website.
Click the ViewPortX extension icon.
Start testing your website across multiple screen sizes instantly.