ScreenTestProScreenTestPro — Free Online Monitor & Screen Tests
Simple, honest tools for checking a new monitor, laptop or phone screen before the return window closes. Everything runs in your browser. Nothing to install, no sign-up, and no data sent anywhere.
Pick a test
Dead Pixel Test
Cycle solid fullscreen colors to spot dead and stuck pixels, then mark them for a warranty claim.
Input Lag Test
Compare click-to-screen latency between settings, or measure true display lag with a camera timer.
Refresh Rate Test
Measure your real Hz, frame-time stability and dropped frames, and check for frame skipping.
Response Time & Ghosting Test
Watch moving targets at different speeds to spot ghosting, smearing and overdrive overshoot.
Backlight Bleed & IPS Glow Test
Fullscreen black and dark-grey screens to check bleed, IPS glow and clouding before the return window ends.
Monitor Color Test
Check gradients, black and white levels, gamma and uniformity to catch crushed blacks and banding.
Text Clarity Test
Find out why text looks blurry: scaling, non-native resolution, ClearType or OLED subpixels.
Viewing Angle Test
See how colors and contrast shift off-axis, and estimate whether your panel is IPS, VA or TN.
Testing a new monitor? Do it in this order
- Dead pixels first. Run the dead pixel test on solid colors. Pixel defects are the easiest problem to prove, and many retailers only accept them in the first days.
- Backlight bleed and IPS glow. Wait until the room is dark, then use the backlight bleed test. Check from straight on and from the side, because that is how you tell bleed from glow.
- Settings. Make sure the monitor is really running at its rated refresh rate with the refresh rate test. A wrong cable or Windows setting often leaves a 144 Hz panel stuck at 60 Hz.
- Picture quality. Check black level, gradients and gamma with the color test, and blurry text with the text clarity test.
- Motion, for gaming screens. Pick the overdrive level with the response time test, then compare settings with the input lag test.
How we build these tests
Every pattern is drawn by the browser at your screen's native resolution, so nothing gets blurred by image compression or scaling. Each test shows the resolution, pixel ratio and refresh rate it detected. If your browser is scaling the page, you will see a warning on the page.
We also say plainly what a browser can't measure. A web page can't read a monitor's true input lag or GtG response time the way a hardware sensor does, so those tools show you how to compare settings and when you need a camera instead.
Questions or a monitor that behaves strangely? Get in touch. Reader reports are how most of these tests got better.