iPhone Dead Pixel Test
Free dead pixel test for iPhone. Run the guided full-screen colour check in Safari, find dead, stuck, and burnt-in pixels on an OLED panel, and see what Apple usually does about it.
Open this page on the iPhone you want to check, then run the guided colour test below. It walks through the six screens that expose the three different faults an iPhone display can have – dead pixels, stuck pixels, and OLED burn-in – and tells you what to look for on each one.
Before you start, take thirty seconds over these. All three make a healthy screen look faulty:
- Clean the glass. A speck of dust on a white screen is indistinguishable from a dead pixel.
- Turn off True Tone, Night Shift, and Reduce White Point (Settings › Display & Brightness, and Accessibility › Display & Text Size). They tint the whole panel.
- Set brightness manually to about half rather than leaving Auto-Brightness on, so the screen does not dim partway through.
Tap the screen to move to the next colour. Tap Exit, press Escape, or double-tap to stop.
What each colour is showing you
On an LCD every pixel sits in front of a backlight, so a pixel that has failed still has light behind it. OLED is different: each sub-pixel makes its own light, and a pixel that is off is genuinely black. That changes which colours are useful, which is why the test runs them in this order.
- White is the main dead-pixel screen. Every sub-pixel should be lit, so any black dot is a dead pixel and any coloured dot is a pixel with one dead sub-pixel (a cyan dot means the red sub-pixel is out, magenta means green is out, yellow means blue is out).
- Black finds pixels that are stuck on. On a healthy OLED the black screen is the same as the phone being off, so any point of light is a stuck sub-pixel. This is also the screen where a bright "hot" pixel stands out most.
- Red, green, and blue isolate one sub-pixel each. A dark dot on the red screen but not on green or blue tells you the red sub-pixel has failed, which is useful if you want to describe the fault precisely to a repair technician.
- Gray is for uniformity and burn-in rather than individual pixels. On a flat mid-gray, look for a faint keyboard, status bar, or app icons ghosted into the panel, and for a tint that differs between the top and bottom of the screen.
OLED iPhones also show a slight colour shift when viewed off-axis, and some models are known for a greenish or pinkish cast at very low brightness on gray. Those are panel characteristics, not defects, and they are not what this test is looking for.
Getting a bar-free screen on iOS
Safari on iPhone and iPad does not support the Fullscreen API for web pages, only for video, so no website can hide the browser bar for you. The test covers the whole viewport instead, which is enough to judge the screen, but if you want every pixel visible:
- Add the page to your Home Screen. Tap the Share icon in Safari, choose Add to Home Screen, and open the test from the icon it creates. It launches without Safari's toolbar, so the colour covers the entire panel.
- Or scroll to shrink the toolbar. A small upward scroll collapses the Safari bar to a thin strip. Rotate to landscape and check the ends of the screen separately if the strip is still in the way.
Hold the phone about 20 centimetres away and scan the screen slowly in a grid rather than staring at the middle. A single pixel at iPhone density is less than a tenth of a millimetre across, so it is easy to sweep straight past one.
Dead vs stuck vs burn-in
These three problems look different and have different outcomes, so it is worth being precise.
A dead pixel is permanently off. It shows as a black dot on every colour except black, never changes, and cannot be fixed by software or by pressing on the screen. The transistor driving it has failed.
A stuck pixel has a sub-pixel frozen in one state. Stuck on, it shows as a red, green, blue, or white dot on the black screen; stuck off, it shows as a coloured dot on white. Stuck pixels sometimes recover on LCD screens after a flashing fixer cycles the sub-pixel rapidly for 10 to 30 minutes. On OLED the success rate is lower, but the stuck pixel fixer is free to try. Do not massage the glass as some older guides suggest; iPhone panels are laminated and pressure can create new damage.
Burn-in is not a single pixel but a region. OLED sub-pixels dim as they age, and areas that showed a bright static element for hundreds of hours (the keyboard, a navigation bar, a game HUD) age faster than their surroundings and leave a faint permanent shadow. It is only visible on uniform content, which is why the gray screen matters. Image retention looks the same but fades within minutes; if the shadow is still there after ten minutes of varied content, it is burn-in. Our burn-in test guide covers this in more depth.
What Apple will usually do
Apple does not publish a numeric pixel-defect policy the way monitor manufacturers do. Its stores and authorised service providers assess screens case by case, and the outcome depends on how visible the defect is, whether the phone is inside its one-year limited warranty or covered by AppleCare+, and the judgement of the technician. Reports from owners suggest that a clearly visible dead or stuck pixel on a phone under warranty is often accepted for display replacement, while a single pixel that the technician struggles to see may be declined as within tolerance.
The one certain route is the return window. If you bought the phone new from Apple, you can return it for any reason within the return period (14 days in most countries), so test it on day one. Carriers and other retailers have their own windows and restocking rules, so check before you rely on them. Burn-in is generally treated as wear rather than a defect and is rarely covered outside of a documented known issue.
Checking a used iPhone before you buy
A screen fault is one of the few problems on a used iPhone that you can verify in under two minutes, so do it before money changes hands.
- Run the test above on the seller's phone and go through white, black, and the three primaries.
- Stop on the gray screen for a while and look for keyboard or status-bar ghosting. Burn-in on a used phone tells you it was used heavily at high brightness, which often means the battery has had a hard life too.
- Check the edges on the black screen for a bright line or a corner that looks lighter, which can indicate a damaged or aftermarket panel.
- Open Settings, General, About and confirm the display shows as a genuine Apple part on models that report it; an "Unknown Part" warning means the screen was replaced with a non-original one.
- Run the touch screen test as well. Replacement screens that look fine can still have dead touch zones or ghost touches, and a screen fault plus a touch fault together almost always means a cheap replacement panel.
If the seller will not let you run these checks, walk away. A working display and digitizer are the minimum for any phone at any price.
Frequently asked questions
How do I test for dead pixels on an iPhone?
Open this page on the iPhone in Safari, tap Start the test, then tap the screen to move through white, black, red, green, blue, and gray. White exposes dead pixels as black or coloured dots, black exposes stuck pixels as points of light, and gray exposes burn-in. Clean the glass first and turn off True Tone and Night Shift, because both can make a healthy screen look faulty.
Why does the test not go properly full screen on my iPhone?
Safari on iPhone does not support the Fullscreen API for anything except video, so no website can hide the address bar for you. The test fills the whole viewport instead. Scroll down slightly to shrink the Safari bar, or add the page to your Home Screen and open it from the icon to get a bar-free view.
Which colour shows dead pixels on an iPhone?
White. A dead pixel is switched off, and on an OLED an off pixel is simply black, so it is invisible on the black screen and obvious on white. Use black to find pixels that are stuck on, and red, green, and blue to work out which sub-pixel is at fault.
Can a dead pixel on an iPhone be fixed?
A truly dead pixel cannot be fixed by software because the transistor or the OLED element has failed. A stuck sub-pixel occasionally recovers after running a flashing fixer for 10 to 30 minutes, but on OLED this works less often than on LCD. Do not press on the glass; it will not help and can damage the panel.
Will Apple replace an iPhone with one dead pixel?
Apple does not publish a pixel-defect threshold. In practice, stores evaluate the screen case by case and many will replace a display that has a visible defect while the phone is under warranty or AppleCare+, but a single tiny pixel is not guaranteed to qualify. Inside the return window you can return the phone regardless of the reason.
Is a faint outline of the keyboard on my iPhone screen burn-in?
If it is visible on a mid-gray screen after the phone has shown other content for a while, yes, it is burn-in, and it is permanent. If it fades within a few minutes it is temporary image retention. Both are most common on phones that ran a static app at high brightness for many hours a day.
Do all iPhones have OLED screens?
No. The iPhone X, XS, 11 Pro, and every iPhone 12 and later flagship use OLED. The iPhone XR, iPhone 11, and all iPhone SE models use an LCD. LCD panels have a backlight, so a dead pixel shows as a dark dot on white and the black screen can reveal backlight bleed around the edges instead.
Does True Tone or Night Shift affect the test?
They tint the whole screen, which can make a uniformity check misleading. Turn off True Tone, Night Shift, and Reduce White Point in Settings before testing, and set brightness manually to about 50 percent, then repeat at maximum.
Last updated 2026-09-27. Everything on this page runs in your browser. Nothing you type or upload leaves your device.