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Phone Screen Test: Test Your Mobile Display Online

A complete mobile screen test you can run from the phone itself. These browser tools check the touch digitizer, the pixels, the backlight and the colours of any Android phone, iPhone or tablet — useful before you buy a used handset, after a screen repair, or when something just looks wrong.

How to Test a Phone Screen in Five Minutes

Work through these steps in order on the phone you want to check. Do it in a dimly lit room with the screen brightness set high — faults that are invisible in daylight show up immediately in the dark.

  1. 1

    Clean the glass first

    Wipe the display with a dry microfibre cloth before you start. Half the “defects” people report on a phone screen test turn out to be grease or lint. Open the white screen full screen and anything still on the glass will be obvious.

  2. 2

    Test the touch layer

    Run the touch screen test and drag a finger across every square of the grid. Any square that refuses to fill in is a dead zone in the digitizer — the most common fault on a dropped or water-damaged phone. Switch to multi-touch mode afterwards to confirm the panel tracks several fingers at once.

  3. 3

    Look for dead and stuck pixels

    Cycle through solid red, green, blue, black and white with the dead pixel test. A dead pixel stays black on every colour; a stuck pixel stays one colour on every screen. Hold the phone about 30 cm away and scan in slow horizontal passes. If you find a stuck pixel, the pixel fixer can sometimes unstick it.

  4. 4

    Check black levels and light leak

    On a black field, an OLED phone should look genuinely black while an LCD phone shows a faint grey glow — that difference is normal. What is not normal is a bright band along one edge or a glowing corner. iPhone owners can use the dedicated iPhone black screen test, which provides a pure black image you can save to Photos and pinch-zoom into.

  5. 5

    Judge colour and burn-in

    Compare white against a sheet of paper to spot a yellow or blue cast, then run the colour accuracy test for banding and saturation errors. Older OLED phones should also get a burn-in test — look for a ghost of the status bar or navigation buttons on a mid-grey field.

Testing an Android Phone vs an iPhone

Android

  • •Turn off adaptive brightness and any blue-light or reading-mode filter before testing, or you will diagnose a colour cast that the software added.
  • •Many Samsung, Xiaomi and OnePlus devices have a hidden hardware diagnostic dialler code. Use it as a second opinion, but run the browser tests first — they work on every brand.
  • •If the phone has a high refresh-rate mode, force it on in developer options before judging smoothness or ghosting.

iPhone

  • •Switch off True Tone and Night Shift in Settings → Display & Brightness. Both warm the white point deliberately and will make a healthy screen look yellow.
  • •For the black test, save the image from our iPhone black screen test to Photos and view it there — Photos gives you true full screen with no browser chrome, and lets you pinch-zoom into suspicious spots.
  • •A faint grey-green tint on a dark OLED iPhone screen at low brightness is a known panel characteristic, not a defect. Judge colour at 60–80% brightness instead.

Frequently Asked Questions

Every test on this page runs in your phone browser, so there is nothing to download. Open the page on the device you want to test, tap a tool, and put it into full screen. Because the tests are just web pages drawing colours and tracking touches, they work identically on Android and iPhone and they cannot see or store anything about your device.

A phone screen test covers the whole display: the panel that produces the image and the touch layer laid over it. A touch screen test covers only the touch layer, or digitizer. A phone can have a flawless picture and a dead touch zone, or perfect touch and a column of dead pixels, so it is worth running both before you decide whether a screen needs replacing.

A sharp, perfectly straight line of one colour running the full height or width of the display is almost always a failed display connector or a damaged driver IC, not a pixel fault. It typically appears after a drop or a screen replacement, and no software test or pixel fixer will clear it — the panel or its ribbon cable needs replacing.

Yes, and it is worth doing before paying for a repair. A cracked cover glass with an intact display and digitizer will still pass the touch and pixel tests, which means you may only need the glass replaced. If the touch test shows dead zones, or you see black blotches or spreading ink-like patches, the damage has reached the panel itself and the whole display assembly needs to go.

Run the full sequence when you buy a phone, when you buy one second-hand, and immediately after any screen repair — those are the moments a fault is still someone else’s responsibility. After that, testing once or twice a year is plenty unless you notice something specific such as a touch dead zone, a colour cast, or ghosting from burn-in.