iPhone Black Screen Test

Download a pure black image, save it to your Photos app, and zoom in to check your iPhone display for dead pixels, backlight bleed, and OLED uniformity issues.

Preview

This is the pure black your test image will be

4096 × 4096 pure black PNG - works on all iPhones and iPads

How to Run the Test

1

Download the image

Tap the blue button above. On iPhone, you will see a download prompt - tap "Download". The image will appear in your Files app or Downloads folder.

2

Save it to your Photos app

Open the downloaded image, tap the Share button (the box with the arrow), then tap "Save Image". This puts it in your Camera Roll where you can view it properly.

3

Max out your brightness

Go to Settings → Display & Brightness and crank the slider all the way up to 100%. Turn off Auto-Brightness (under Settings → Accessibility → Display) and disable True Tone. This gives you raw, unfiltered output from the display.

4

Go to a dark room

Turn off the lights. Close the curtains. The darker the room, the easier it is to spot even the faintest backlight bleed or glow. Ambient light washes out subtle defects.

5

Open the image and zoom in

Open the black image in Photos and pinch to zoom in slightly. This is the key step - zooming pushes the clock, battery icon, and the home bar off the edges of the screen, giving you a 100% pure black canvas edge to edge. Now slowly scan across the entire screen.

OLED iPhones

iPhone X, XS, 11 Pro, and every iPhone 12 through 16 model. The screen should look completely turned off. OLED pixels physically shut off to produce black. If you see grayish glowing spots or unevenness, that is a display defect.

LCD iPhones

iPhone 8, XR, 11, and SE models. You will see a faint uniform glow across the screen - that is normal. LCD panels use a backlight that cannot fully shut off. You are looking for bright patches (backlight bleeding) or tiny colored dots (stuck pixels).

Why the Photos App Trick Actually Works

If you have ever tried opening a black screen website on your iPhone and thought "this does not really help," you are not wrong. Safari keeps the status bar visible at the top, the home indicator bar sits at the bottom, and there is no real way to get a completely black edge-to-edge display from the browser alone.

That is where the Photos app comes in. When you open a full-size black image in Photos and pinch to zoom in just slightly, all of the system UI gets pushed off the screen. What you are left with is a true, uninterrupted black canvas covering every pixel on your display. That is what makes this method so effective compared to trying to do it in a browser.

Getting Your iPhone Ready for the Test

Before you run this test, there are a couple of settings you should change to get accurate results. Your iPhone has some clever features that automatically adjust your display, and they are great for daily use, but they get in the way when you are trying to evaluate the raw hardware.

Settings to Change Before Testing

  1. Brightness to 100%: Swipe down from the top-right corner and drag the brightness slider all the way up. You want maximum output so defects are as visible as possible.
  2. Turn off Auto-Brightness: Go to Settings → Accessibility → Display & Text Size → scroll down and toggle off Auto-Brightness. If you leave this on, your phone will dim the screen in a dark room, which defeats the purpose.
  3. Turn off True Tone: Go to Settings → Display & Brightness and toggle off True Tone. This feature adjusts the color warmth of your display based on room lighting, and you do not want that interference during a test.
  4. Turn off Night Shift: While you are in Display & Brightness, make sure Night Shift is off too. The orange tint will mask subtle color defects.

What Your Screen Should Look Like

What counts as "normal" depends entirely on which type of display your iPhone has. Apple has used two fundamentally different screen technologies across different models, and they behave very differently on a black screen test.

OLED iPhones (iPhone X and Later)

If you have an iPhone X, XS, 11 Pro, 12, 13, 14, 15, or 16 (any model), your phone uses an OLED display. On an OLED panel, every pixel produces its own light independently. When a pixel needs to show black, it simply turns off completely. No backlight, no glow, nothing.

So when you open the black test image, your screen should look like it is turned off. The entire display should be uniformly dark. If you spot any grayish patches, faint glowing areas, or tiny bright dots, you have found a defect. Common OLED issues include uneven brightness on very dark grays (sometimes called "black crush") and green or purple tinting at low brightness levels.

LCD iPhones (iPhone 8, XR, 11, SE)

If you have an iPhone 8, 8 Plus, XR, 11, or any generation of the iPhone SE, your phone uses an LCD (IPS) panel. LCD screens work differently - there is a backlight behind the entire panel that stays on all the time, even when displaying black. The liquid crystals try to block the light, but they cannot block it 100%.

So on an LCD iPhone, you will always see a faint, uniform glow across the whole screen during a black screen test. That is completely normal. What you are actually checking for is whether that glow is even. If you see specific bright spots or lighter patches around the edges or corners, that is backlight bleeding, which means the backlight is leaking through the edges of the panel more than it should.

Common Things People Find During the Test

  • Bright dot that will not go away: That is a hot pixel or stuck pixel. It is a hardware defect. On OLED screens, try our dead pixel fixer tool to see if rapid color cycling can unstick it.
  • Faint glow in one corner: On LCD phones, this is backlight bleeding. Mild bleed is common on nearly all LCD panels and is usually not worth worrying about unless it is distracting during normal use.
  • Green or purple tint at low brightness: Some OLED iPhones show a slight green or purple tint on very dark screens at low brightness. This is a known characteristic of certain OLED panels. If it is subtle and only visible in pitch darkness, it is within normal range.
  • A small dark spot that stays dark on all colors: That is a dead pixel. It will show up more clearly if you also test with a white screen.

When to Actually Worry

Most people who run this test are doing it because they just bought a new or used phone and want to check it, or because they noticed something odd during normal use. Here is a quick rule of thumb:

If the defect is only visible in a pitch-black room on a pure black image at full brightness, it is probably not going to bother you during daily use. Every display has minor imperfections if you look hard enough. But if you can see uneven glow, bright spots, or stuck pixels during normal daily use - reading, browsing, watching videos - that is worth contacting Apple Support or visiting an Apple Store about, especially if the phone is still under warranty or AppleCare+.

Already Tested With Black?

A black screen only reveals half the picture. Dead pixels (pixels that are permanently off) are invisible on a black background. To catch those, you need to test with a white screen or use our full dead pixel test which cycles through multiple colors. And if you want to check overall color accuracy or whether your display has a yellow tint, we have tools for that too.

Frequently Asked Questions

When you open a black screen in Safari, your iPhone still shows the clock, battery icon, signal bars, and the home bar at the bottom. These bright UI elements make it impossible to check the full screen. By downloading the image and opening it in the Photos app, you can pinch to zoom in slightly, which pushes all of those elements off the edges and gives you a truly pure black canvas covering every single pixel.

On an OLED iPhone (iPhone X and newer Pro models, and all iPhone 12 through 16 models), the screen should look completely turned off. OLED technology shuts off individual pixels to produce true black. If you see any grayish glow, faint light spots, or uneven patches, that indicates a display defect.

It depends on your model. If you have an LCD iPhone like the iPhone 8, XR, 11, or SE, yes, a faint uniform backlight glow is completely normal because LCD screens cannot fully turn off pixels. However, if you have an OLED iPhone and see glowing, that is a defect. Also check for uneven bright patches on LCD models, which indicates backlight bleeding.

True Tone adjusts the color temperature of your display based on the ambient light in the room, and Auto-Brightness automatically lowers or raises the screen brightness. Both features change what you see on screen in real time. During a display test, you want the raw, unmodified output from your panel, so turning both off ensures your results are accurate and repeatable.

Absolutely. The same process works on any iPad. Download the black PNG, save it to Photos, open it, and zoom in. The 4096x4096 image is large enough to cover even the highest resolution iPad displays without any pixelation or upscaling artifacts.

On a black background, a dead pixel will just blend in and be invisible because it produces no light. What you are looking for on a black screen are hot pixels (pixels that are always on and appear as tiny bright white dots) and stuck pixels (tiny dots of color, usually red, green, or blue). To check for dead pixels specifically, you would need to test with a white or colored background instead.

Resources & Communities

Looking for more help? Check out these popular communities and resources.

r/mobilerepair
Community for mobile device repair and digitizer issues.
XDA Developers
Top community for Android hardware discussion and tweaking.
iFixit
Detailed teardowns and repair guides for touch screens.