Viewport Size Checker
Check your browser viewport width and height in pixels. Useful for web developers testing responsive designs.
How does this test work?
A viewport size checker shows the inner dimensions of your browser window — the area available for web content. Resize your browser to see values update in real time.
How to use the Viewport Size Checker
Open the Viewport Size Checker on any device with a modern browser — desktop, laptop, tablet, or phone. No downloads, plugins, or signup required. The tool loads instantly and works in Chrome, Firefox, Safari, Edge, and other Chromium-based browsers.
Follow the on-screen instructions to run the test. Results are displayed immediately in your browser. You can repeat the test as many times as needed. For the most accurate results, close other tabs and applications to reduce interference.
Privacy: This test runs entirely in your browser using standard web APIs. No data is collected, uploaded, or stored on any server. Camera, microphone, keyboard, mouse, and controller inputs are processed locally and never leave your device. DeviceKit does not use analytics cookies or tracking scripts.
Browser note: Some hardware values are estimated because browsers limit direct access to device hardware for security and privacy reasons. Results may vary slightly between browsers and operating systems. For the most reliable measurements, use an up-to-date version of Chrome or Edge on a desktop computer.
Frequently Asked Questions
What is the viewport?+
The viewport is the visible area of a web page in your browser. It excludes browser toolbars, tabs, and scrollbars. Web developers use viewport dimensions for responsive design.
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Screen Size Checker
Check your screen size, resolution, viewport dimensions, and device pixel ratio instantly in your browser.