Viewport
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Dead pixel test
Dead Pixel Test and Screen Test Online
Run a fullscreen dead pixel test, colour screen test online, monitor ghosting test, refresh-rate motion check and colour-difference inspection. Browser tests are approximate and can be affected by display settings, browser zoom, battery mode, open tabs, cables and panel technology.
Flashing test may not be suitable for people sensitive to flashing lights.
Ready. Use the large controls or arrow keys to switch tests.
Screen
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Pixel Ratio
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Colour / HDR
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Orientation
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Refresh Rate
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Black
Export Screen Diagnostic Report
Export a laptop diagnostic report or computer diagnostic report online with browser details, marked pass/fail/not sure results and your notes.
IPS Glow, Backlight Bleed and HDR Notes
IPS glow often changes with viewing angle and is common on IPS panels, while backlight bleed usually appears as fixed bright patches near edges on black screens. HDR support can be hinted by browser media queries, but a browser cannot verify true HDR brightness, local dimming quality or panel calibration. Use this test as a practical first check, not a lab-grade measurement.
About the screen and dead pixel test
The screen test combines two things: readouts of what your browser knows about the display — resolution, pixel ratio, orientation, colour and HDR hints, and a measured refresh rate — and a set of fullscreen visual checks. Solid black, white, red, green and blue panels reveal dead or stuck pixels; gradients expose banding; grids show scaling blur and geometry problems.
Dead pixel hunting works best with the panels at fullscreen and your eyes about arm’s length from the screen. A dead pixel stays black on every colour; a stuck pixel glows in one colour on the others; dust wipes off — it is worth checking with a cloth before worrying. On black, also look along the edges for backlight bleed, the fixed bright patches that matter far more on a panel you are about to buy than a marketing spec sheet does.
This page is a practical inspection tool, not a calibration instrument. It will catch the faults that actually change a buying or warranty decision — dead pixels, heavy bleed, obvious colour cast, scaling blur — in a few minutes. For print-accurate colour work you would still need a hardware calibrator.
What it looks like in use
Understanding display results
The display test combines browser-reported screen details with visual colour, gradient and grid checks. It is designed for quick inspection rather than laboratory calibration.
What this test checks
- Viewport size, available screen size, device pixel ratio and orientation reported by the browser.
- Colour bands for spotting obvious tint, channel failure or severe banding.
- Gradient and grid patterns for checking scaling, blur, uneven brightness and alignment.
- Fullscreen behaviour so you can inspect more of the panel without browser chrome.
How to understand your results
- A good display shows smooth gradients, readable text, straight grid lines and consistent colour blocks.
- One or two stuck pixels may be hard to see in a browser; inspect fullscreen colour panels carefully at normal brightness.
- If text looks blurry, check operating system scaling, browser zoom and external monitor resolution.
- Colour accuracy cannot be certified here. Use a hardware calibrator for print, design or grading work.
Common problems and fixes
Blurry external monitor
Set the monitor to its native resolution, use a suitable cable and check that scaling is not excessive.
Odd colour cast
Disable night light, True Tone or blue-light filters, then compare against another display.
Dead or stuck pixels
Use fullscreen colour panels and inspect at a sensible distance. Warranty policies vary by manufacturer.
Browser zoom affects layout
Reset browser zoom to 100 percent before using the grid and text clarity sections.
FAQ
Can a browser detect dead pixels?
A browser can show solid colours and patterns that help you visually find dead or stuck pixels, but it cannot automatically inspect every physical pixel.
What is the difference between a dead pixel and a stuck pixel?
A dead pixel stays black on every colour panel; a stuck pixel shines in one fixed colour. Stuck pixels sometimes recover on their own or with gentle massage techniques — dead ones generally do not.
Can this screen test measure ghosting exactly?
No. The motion and ghosting patterns are visual checks affected by refresh rate, panel response, browser timing, settings and your eyes.
Is the HDR check exact?
No. Browser APIs can expose hints, but exact HDR brightness, colour accuracy and calibration need specialist tools.
How many dead pixels justify a warranty claim?
Policies differ by manufacturer and panel class — some accept a single bright pixel, others require several. Count and photograph what you find here, then check the maker’s pixel policy before claiming.
Why does device pixel ratio differ from resolution?
High-DPI screens map several physical pixels to one CSS pixel for sharper text. A ratio of 2 on a "1440p" laptop means the physical panel is actually far denser than the working resolution suggests.
Browser-based test disclaimer
TestMyPC results are browser-based and may vary depending on your device, browser, operating system, permissions, drivers, connection, power settings and connected accessories. Use these tools as practical first checks, then confirm important faults with operating-system diagnostics, manufacturer tools or a qualified technician where needed.