Screen resolution
Measuring…
← All tools
Live browser diagnostic
Browser Size Checker
Watch the browser viewport size update while resizing the page.
Current browser viewport size
Measuring…
The live browser viewing area available to this page, not the physical monitor size.
Resize-aware
The value updates as the browser viewport changes.
Bug reports
Useful for QA and frontend teams.
Layout checks
Confirms active desktop/tablet/mobile CSS widths.
Share result link/card
Generating share card…
Full diagnostics
Detailed browser, display, viewport, DPR, OS, orientation, color depth, and refresh-rate values.
Current viewport
Measuring…
This is the CSS viewport your website sees.
Device pixel ratio
Measuring…
Visual viewport
Measuring…
Browser
Measuring…
Operating system
Measuring…
Orientation
Measuring…
Color depth
Measuring…
Refresh rate
Measuring…
Zoom/scaling note: Checking…
Share result link/card
Generating share card…
How to use this result
Browser size here means the browser viewport: the live page area available to CSS and JavaScript. Resize the browser and this value updates automatically.
Copy the focused viewport size or the full diagnostics when reporting responsive bugs to design, development, or QA teams.
Privacy note
This MVP checker runs in your browser. It does not require signup, file uploads, or personal account data to show your screen metrics.
MVP checker guide
When browser size matters
Browser size here means the browser viewport: the live page area available to CSS and JavaScript. It is useful when a layout only breaks at a specific window width or height, and it updates live as you resize the page.
Reproduce layout bugs
Resize your browser until the issue appears, then copy the browser viewport and full diagnostics.
Check responsive states
Confirm when a design changes from desktop to tablet or mobile layout.
Share full environment
Copy all details to include browser, OS, DPR, color depth, and orientation with the browser size.
Frequently asked questions
What does browser size mean here?
Browser size here means the viewport area available to the webpage, not the physical monitor size or the full browser application frame.
Why does the value change while resizing?
The checker listens for window and visual viewport resize events, so the measurements update automatically.
Can I use this for QA notes?
Yes. Copy the full details and attach them to bug reports or design feedback.
Is browser size the same as monitor size?
No. Browser size is the web page viewing area, while monitor size is the physical display.
Content cluster
Related guides
Use these supporting guides to understand the tool result and next testing steps.
Related tools
Continue with another ScreenMetricLab utility.