Display Tests
Find dead and stuck pixels, try to bring a stuck one back, and confirm your monitor runs at the refresh rate it was sold at.
- Dead Pixel TestFills your screen with solid colors, one at a time, so dead and stuck pixels stand out. Works on monitors, laptops, TVs and phones.
- Stuck Pixel FixerFlashes rapidly changing colors over a stuck pixel to try to bring it back. Drag a small flashing square over the pixel, or flash the whole screen.
- Refresh Rate TestMeasures the real refresh rate of your screen, checks it against the rate it is sold at, like 144 Hz, and counts dropped frames.
- HDMI Bandwidth CalculatorWorks out the data rate your resolution, refresh rate and color depth need, and which HDMI and DisplayPort versions and cables can carry it.
- Monitor Ghosting TestMoves a block across dark, gray and light backgrounds so you can see ghosting trails and overdrive overshoot on your monitor.
Which Test Do You Need?
Just bought a screen? Run the dead pixel test first. It fills the screen with solid colors so faulty pixels stand out.
Found a dot stuck on one color? The stuck pixel fixer flashes colors over it to try to bring it back.
Paid for a high refresh rate? The refresh rate test shows the rate your screen really runs at.
Seeing trails behind moving things? The monitor ghosting test moves a block across dark, gray and light backgrounds, and says which monitor setting to change.
Stuck at 60 Hz, or buying a cable? The HDMI bandwidth calculator shows whether HDMI or DisplayPort can carry your resolution and refresh rate, and which cable to use.
Checking a New Monitor or Laptop Screen
Clean the screen first with a dry microfiber cloth. On a solid color, a speck of dust looks exactly like a dead pixel.
Test while you can still return it. Most makers replace a panel only past a set number of faulty pixels, so count them with the dead pixel test and check the policy before the return window closes.
A pixel stuck on one color may come back, so run the stuck pixel fixer on it before you send the screen back.
Bought a 144 Hz or faster monitor? The refresh rate test shows the rate it really runs at. The rate is set in your system’s display settings, and the cable has to carry it: the HDMI bandwidth calculator shows which HDMI or DisplayPort version and cable can.
Frequently Asked Questions
How do I check a new monitor for problems?
Run the dead pixel test in full screen and look at each color from your normal viewing distance, then run the refresh rate test. Together they cover the faults a new screen is most often returned for: dead or stuck pixels, and a monitor running slower than it was sold at.
Can a stuck pixel fix itself?
Sometimes. A pixel stuck on one color can start working again on its own, or after the stuck pixel fixer flashes colors over it. A dead pixel, which stays black on every color, does not come back.
Do these tests work on a laptop, TV or phone screen?
Yes. Open the page on the device, or on a computer connected to the TV, and go full screen. The pixel tests work on any screen; the refresh rate test measures the screen the browser window is on.