Which screen test do you need?
- You see a dot that never changes: run the dead pixel test. If the pixel is stuck on one colour, try the stuck pixel fixer on the same page.
- You are checking a new or second-hand monitor: the monitor test covers uniformity, gamma and banding. Use the black screen in a dark room for backlight bleed.
- You paid for a high refresh monitor: the refresh rate test shows the rate you really get, and the UFO test shows motion blur.
- You need a plain light or a clean background: use the white screen.
- You need your screen details: the screen resolution test lists them all.
Touch screens, styluses and phone sensors have their own page: touch and mobile tests.
Frequently asked questions
Short answers to common questions about these tests.
How do I check a monitor before buying it used?
Run the dead pixel test on every colour, show the black screen in a dark room for backlight bleed, run the monitor test patterns and check the refresh rate. It takes about five minutes.
Can a website fix a stuck pixel?
Sometimes. The stuck pixel fixer flashes colours fast over the pixel, which can free a slow liquid crystal. A dead pixel that stays black cannot be fixed by software.