Color & dead pixel test
Tap the screen during the test to go to the next color
Advanced tests
Backlight, gradients, motion and touch
DeviTest
Test your screen, keyboard, mouse, sound and camera in the browser
Ready
🌐 …
Test your whole device — free, in your browser
Screen, keyboard, mouse, sound, microphone and camera. Nothing to install and nothing is uploaded. Start the full check, or pick a single test below.
All tools
Pick a test by device
⌨️ Keyboard, mouse & controller
Keyboard testFind dead or sticky keys
Mouse testButtons, wheel and double-click check
Gamepad testButtons, triggers and stick drift
🎧 Sound & camera
Sound testLeft / right, bass and frequency range
Mic testLive level and a 5-second recording
Camera testResolution and frame rate
Video call readinessCamera, mic, speakers and WebRTC
🖥️ Screen tools
White & color screenFull-screen white, black and colors
Dead pixel locatorMark faulty pixels and save a map
Viewing angle & gammaCheck mid-tones and color shift
Contrast testBlack level and white saturation
Screen rulerReal-size ruler in cm and inches
PPI calculatorPixel density and real screen size
📱 Phone
Phone hardware testSpeakers, mic, vibration, multi-touch, sensors
Used phone screen checkA checklist before you buy
🩺 Full check & diagnostics
Full device checkStep by step, with a report — ideal before buying used
Device & browser infoScreen, browser, features and permissions
Internet speed testDownload, upload and ping
Latency & jitter testHow steady is your connection?
⚡ Speed & reflexes
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Test your screen
Find dead pixels, color problems, bleed, blur and touch issues
Fix & screen info
Try to revive a stuck pixel and see your screen specs
Stuck pixel fixer
Rapid color flashing that can wake up a stuck pixel
This mode contains rapid flashing. Do not use it if you or anyone nearby has photosensitive epilepsy. You can leave it running without looking at it.
⚡ Speed
🎨 Color pattern
⏱ Session length
Screen info
Your device as the browser sees it
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Native resolution
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Refresh (Hz)
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Color depth
Viewport (CSS)
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Pixel ratio (DPR)
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Color gamut
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HDR support
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Touchscreen
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OS / Browser
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Guides & help
Learn what the results mean
Fix a stuck pixelWhat works and what doesn't
Dead pixel testDead vs stuck pixels explained
Banding testWhy gradients show stripes
All guides & testsEvery guide in one place
How to use & FAQ
Check your screen step by step
Step-by-step screen check
- Clean the screen first so you don't mistake dust for a dead pixel.
- Start the color test and tap to cycle. A pixel that stays black on white is "dead"; one that stays colored on black is "stuck".
- Found a stuck pixel? Use the targeted fix and drag the square over it for 10–30 minutes.
- For backlight bleed: turn off the lights, set brightness to max, and watch the edges on the black screen.
Keyboard shortcuts
- D Start the color test or go to the next color
- ← → Space Navigate inside a test
- H Hide/show the overlay controls
- Esc End the test
FAQ
Can this tool fix a dead pixel?
No. A dead pixel (always black) is usually a hardware fault that software can't fix. The tool may help a stuck pixel (always colored), with no guarantee.
Is the flashing safe for my screen?
Yes, changing colors doesn't harm the display. It can be dangerous for people with photosensitivity, so it's best not to watch it.
Does the site measure response time in milliseconds?
No browser can measure pixel response time accurately; that needs a camera or photosensor. The ghosting test lets you see trails behind moving objects and compare displays visually.
Is any data uploaded from my device?
No. All tests run locally in your browser, and work offline after your first visit.
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