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MacBook screen test: find dead pixels, lines and damaged areas
A free full-screen test for your Mac's display. It shows solid colours that make dead and stuck pixels stand out, a gradient that shows dark patches and backlight problems, a grid that shows lines, and a ruler along every edge so you can measure exactly how much of the screen is damaged.
- Close other windows and turn the brightness up.
- Click Start. The test fills the whole screen.
- Click, or press the Space bar or arrow keys, to go to the next screen. Press Escape to stop.
- Look slowly across each screen, especially the edges and corners.
Finished the test. If you found a dead strip or garbled band along one edge, the rest of your screen still works. See what to do next.
What each screen shows
| Screen | Look for |
|---|---|
| Black | Bright or coloured dots, which are stuck pixels, and light leaking at the edges. |
| White | Black dots, which are dead pixels, dark patches and pressure marks. |
| Red, green, blue | Pixels that stay dark in one colour, and coloured lines. |
| Grey | Uneven brightness, blotches and yellow or pink areas. |
| Gradient | Bands, steps or a dark area that interrupts the smooth fade. |
| Grid | Lines that are missing, doubled or bent, and areas where the grid disappears. |
| Edge ruler | How far in from each edge the picture stops. The numbers count from the edge, in screen points. |
What your results mean
- One or two dead or stuck pixels. Usually nothing to worry about. See dead pixels vs stuck pixels.
- Lines that stay in place. Damage to the panel or its cable. See lines on the screen.
- Dark patches or blotches. Usually pressure damage. See black spots and pressure marks.
- A dead or garbled strip along one edge. The panel is damaged there, and the edge ruler shows how wide the strip is. See one side of the screen black or bottom of the screen.
- Thinking about a repair? The repair cost calculator shows Apple's own prices for your model.
For a closer look at one problem, use the dead pixel test, the backlight bleed test or the screen flicker test.
Questions
How do I test my MacBook screen?
Run a full-screen test that shows solid colours, a gradient and a grid, and look slowly across each one. Dead pixels, lines, dark patches and damaged edges all stand out. This page does it in your browser, with nothing to install.
How can I tell how much of my screen is damaged?
Use the edge ruler at the end of the test. The numbers count in from each edge, so you can read off exactly where the working part of the screen begins.
Is a damaged MacBook screen still usable?
Often, yes. If the damage is a strip along one edge, the rest of the panel usually keeps working. You can block off the damaged part and keep using the rest.
Found a dead strip along an edge?
CrackMac keeps windows, the menu bar and the pointer on the part of the screen that still works, and paints the dead strip black. You set it up the same way the edge ruler works: drag a line on a picture of your screen where the good part ends.
- Works on macOS 13 or later, Apple silicon and Intel.
- Free for 30 minutes of use, then a one-time price. No subscription.
- A refund within 7 days, no questions asked.