Monitor tests

Check a new monitor before the return window closes, or make sure your expensive high refresh rate screen is really running at full speed.

Dead pixel testFill the screen with solid colours to spot dead, stuck and hot pixels or backlight bleed.Refresh rate testSee the real refresh rate of your monitor in Hz and check that your 144 Hz screen is not stuck at 60.

Monitor checks

What these monitor tests check

The dead pixel test fills your entire screen with solid colours — black, white, red, green and blue. A dead pixel stays black on every colour, a stuck pixel stays lit in one colour, and a hot pixel shows up as a bright dot on black. The black screen also reveals backlight bleed and glow around the edges of LCD panels.

The refresh rate test measures how often your browser can draw a new frame, which matches the refresh rate your monitor is actually running at. It is the quickest way to spot a 144 Hz or 240 Hz screen that is accidentally stuck at 60 Hz because of a setting or a cable.

Both tests run entirely in your browser, take seconds and need no software, so you can check a monitor in a shop, at a friend’s place or right after unboxing.

Frequently asked questions

Should I test a new monitor straight away?

Yes. Most shops and manufacturers only accept returns for dead pixels or backlight problems for a short time, so run the dead pixel test on the first day.

Do these tests work on laptops, phones and TVs?

Yes. Any screen with a modern browser works, including laptop panels, phones, tablets and smart TVs with a built-in browser.

Why does my refresh rate show 60 Hz on a 144 Hz monitor?

Usually the display settings in Windows or macOS are still set to 60 Hz, the cable cannot carry the higher rate, or the monitor is connected to the motherboard instead of the graphics card.