Device BenchScreens, pixels & touch
Display tests.
Eight browser tools help you inspect a display. Check pixels with solid colors, trace touches across a grid, or use the four white, black, red and grey fields for different screen checks. Other tools measure animation-frame timing or use bank-card calibration to estimate pixel density and physical size. All run in this tab without installing an application.
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Dead Pixel TestInspect solid colors for dead, stuck and hot pixels. An optional flashing mode attempts to free stuck pixels; it is not a guaranteed repair.
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Screen Resolution TestRead the browser-reported resolution. Use a bank card to calibrate estimates of pixel density in ppi and the display's physical size.
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White ScreenShow a white field for video-call lighting, tracing or pixel inspection. Six other static colors are available.
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Black Screen TestInspect a black field for backlight bleed, glow, stuck pixels and dust, taking room lighting and panel type into account.
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Red ScreenInspect a red field for subpixel and uniformity problems, or lower your display brightness to use it as a dim red light.
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Grey ScreenLook for blotches, banding and color casts against neutral mid-grey, including dirty screen effect and mura.
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Refresh Rate TestMeasure browser frame delivery with its jitter and range. It usually follows display refresh rate, but is not a direct hardware reading.
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Touch Screen TestTrace the grid with a finger to check which touches register. Numbered markers track the simultaneous contacts reported to the browser.
Why the four solid fields are separate
Each solid color makes different faults easier to see, so the pages serve different purposes despite sharing fullscreen controls. Use the table to choose a field. The measurement methodology explains why judging what appears on the screen is your task rather than a browser measurement.
| Field | Primary job | What to look for |
|---|---|---|
| White | Bright backdrop, tracing light, and dark-pixel contrast | Dark dots, dust, edge tint, or a clean light field |
| Black | Dark-room panel check | Backlight bleed, glow, and bright or always-on pixels |
| Red | One-channel isolation and dim red work light | A failed red subpixel or uneven red-channel output |
| Grey | Mid-level uniformity | Banding, mura, dirty-screen effect, and colour cast |