A dead pixel test for iPad is a visual inspection that fills the iPad screen with solid colors, one at a time, so you can scan for points that stay dark, stay bright, or show the wrong color against the surrounding field. The most reliable way to run this on an iPad is a browser-based fixture that cycles through eight exact sRGB colors in fullscreen inside the Safari or Chrome tab, with no app to install and nothing uploaded. The Dead Pixel Test does exactly that: it requests fullscreen on a single button press, then advances through black, white, red, lime, blue, cyan, magenta, and yellow using a tap, the Space key, or the on-screen arrows. A point that stays dark on white, stays bright on black, or shows an unexpected tint against any of the primaries is the kind of stationary mismatch you would record. The check itself does not repair anything and does not diagnose hardware; it only gives you a controlled stimulus so your eye can compare.
Why iPad Screens Need a Visual Check
An iPad's Liquid Retina and Ultra Retina XDR panels use millions of individually addressable subpixels, and a small fraction of them can fail or lock at one channel value without obvious symptoms during normal use. Most apps show mixed colors, gradients, and text, which makes a single bad pixel easy to miss. A solid-field test removes that camouflage: when the whole panel shows the same color, any point that does not match stands out. Apple does not advertise a zero-dead-pixel guarantee for iPad screens, which is why buyers often run a check within the return window, why refurbishers and resellers run one before grading a device, and why creators who do color-critical work on an iPad run one before locking in a calibration. The test is also cheap: it costs nothing, takes under two minutes, and works on any iPad that can open a modern browser tab in landscape or portrait orientation.
How a Browser-Based Dead Pixel Test Works on iPad
The fixture behind the Dead Pixel Test is small and deliberate. It uses the eight solid CSS sRGB colors defined by the W3C CSS Color Module Level 4 named-color list and verified against the MDN named-color reference. Each color is applied as the background of a single large focusable panel, with a label that names the current pattern, its index, and its exact hexadecimal value. Navigation wraps both forward and backward, fullscreen is requested only from the Start button, and if Safari or Chrome rejects fullscreen the in-page panel keeps working so you can still inspect the screen.
| Pattern | CSS name | Hex value | Channels lit |
|---|---|---|---|
| Black | black | #000000 | All channels off |
| White | white | #ffffff | All channels on |
| Red | red | #ff0000 | Red only |
| Lime | lime | #00ff00 | Green only (full channel) |
| Blue | blue | #0000ff | Blue only |
| Cyan | cyan | #00ffff | Green + blue |
| Magenta | magenta | #ff00ff | Red + blue |
| Yellow | yellow | #ffff00 | Red + green |
The CSS named color for the full green channel is lime, not green: the W3C CSS Color specification reserves green for #008000, a darker shade that does not isolate a single subpixel. The full-channel lime is what makes stuck red or blue subpixels easiest to spot.
Why eight and not more? The three RGB primaries, plus black and white, are the minimum set needed to assert each subpixel channel independently. Cyan, magenta, and yellow add the channel-pair combinations, which is where a stuck green or stuck red subpixel is often easiest to see. Different fields make different visual mismatches easier to notice: a point that stays dark on white may not emit at all, while a point that remains bright or shows an unexpected component can stand out against black or one of the primaries.
Run a Dead Pixel Test on Your iPad
- Power the iPad off and clean only the outer display surface using Apple's safe method: a soft, slightly damp lint-free cloth, with no sprays, solvents, or abrasive wipes. Power back on, open Safari or Chrome, navigate to the Dead Pixel Test page, and tap Start fullscreen test. Accept the browser's fullscreen prompt so the test takes over the whole display.
- Inspect the eight solid fields in order: black, white, red, lime, blue, cyan, magenta, and yellow. Tap the panel to advance, use the on-screen arrow controls, or press the spacebar on an attached keyboard. The progress line at the bottom always names the current pattern, its position, and its exact hex value so you know exactly what you are looking at.
- Spend several seconds on each field and let your eye scan the edges, corners, and center. Record any stationary point that stays dark on white, stays bright on black, or shows a tint that does not match the surrounding field. Use the backward arrow to revisit a color if you spot something suspicious, and look for the same point on at least two different fields before you mark it.
- Exit fullscreen with the browser's normal controls — tap Done on iPadOS or press Escape on a connected keyboard — and run Apple's built-in diagnostics or contact Apple Support before deciding on any repair.
What Each Color Reveals on an iPad
A point that stays dark against every field, including white and the bright primaries, behaves like a dead pixel — it no longer emits. A point that stays bright against every field, including black, behaves like a stuck "on" subpixel. The most informative test is on the three single-channel primaries: red, lime, and blue. A pixel that looks correct on red but looks wrong on lime points to a green subpixel issue; a pixel that looks correct on red and lime but wrong on blue points to a blue subpixel issue. Cyan, magenta, and yellow then light two channels at once, which is where a single-channel failure tends to look most obvious. White confirms whether all three channels are firing together; black confirms whether anything is firing when it should not. For a deeper walkthrough of the color logic, see the guide on what each color reveals in a dead pixel test.
iPad-Specific Things That Can Mimic Dead Pixels
On an iPad, several non-panel issues can produce a stationary spot that looks like a dead pixel but is not. Knowing the difference matters before you open a support case.
| Symptom on the iPad | Likely cause | What it actually is |
|---|---|---|
| A small bright dot on a dark image | Stuck "on" subpixel | Panel defect |
| A small dark dot on any bright image | Dead subpixel | Panel defect |
| A faint round smudge that shifts when you tilt the iPad | Pressure mark, oil, or trapped dust | Outer surface or protective layer |
| A bright line or band along one edge | Backlight bleed or local dimming artifact | Panel-level, but not a single pixel |
| A patch that lingers after a bright image | Image retention | Temporary, often fades within minutes |
| A faint repeating pattern across the whole panel | Subpixel layout or scaling | Normal rendering, not a defect |
| A speck that disappears when you tap the screen gently | Loose particle on the surface | Outer surface, not the panel |
Other iPad-specific confounders include True Tone and Night Shift, which shift the panel's white point, and ProMotion, which can change perceived flicker at 120 Hz. Screen protectors add a second reflective layer that can trap dust, and a swapped protector often "fixes" what looked like a panel issue. Brightness set very low can hide stuck-on subpixels against black, so set it near the top before the test.
After the Check: What to Do With the Results
If you find no stationary mismatch across all eight fields at full brightness, with True Tone and Night Shift temporarily disabled, the panel passed the visual aid. If you find one stationary mismatch, the visual aid has done its job: it flagged a point that does not match its surroundings. Whether it is repairable, in-warranty, or out-of-warranty is not something the test can decide. Apple's own diagnostics, an Apple Store appointment, or an authorized service provider is the right next step. Take screenshots on the iPad before you go, but remember that a screenshot captures what the GPU sent to the panel, not the panel itself — a true physical defect generally does not appear in a screenshot, while a rendering issue might. The check is the start of a conversation, not the end of one.
Privacy and Limits of This Visual Check
The Dead Pixel Test does not upload anything: no screenshot, no display identifier, no color profile, no navigation history. The current pattern index lives only in the tab and resets on reload. Fullscreen is requested only after you tap Start; if Safari or Chrome declines, the in-page panel still cycles through all eight patterns. The tool does not change brightness, lock the operating system, force kiosk mode, disable sleep, or hide the browser's normal Escape behavior. The CSS color value is the requested stimulus, not a measured output from your panel: browser color management, iPadOS display profiles, HDR modes, panel gamut, scaling, subpixel layout, viewing angle, local dimming, image enhancement, burn-in protection, and hardware calibration can all change how a color looks on the glass. A visible mismatch on the iPad is therefore a starting observation, not a hardware certificate, and you should not apply pressure, heat, or any "pixel-fixing" trick on the strength of a single visual check.
Related reading: Dead Pixel Test for Laptop Screens: Run a Visual Check.