Monitor Test

Pick a screen test from the list: most open full screen in one press.

This monitor test is a set of screen tests for the display in front of you: a monitor, a laptop, a phone or a TV. Start with the dead pixel test, then open the test for whatever you noticed.

43 pages

0–9, A 7

4:4:4 Test PatternPress Go full screen and look close: red and blue lines as crisp as the black and white mean 4:4:4.
4K Monitor TestRead your real pixel count, then tap or click Go full screen and step through ten one-pixel patterns.
60Hz TestPress Start to count the frames a second your browser draws and read them against 60.
120Hz TestPress Start: ten seconds later you see the frames a second your browser draws, read against 120.
144Hz TestPress Start: after ten seconds the number is the frames a second your browser is drawing, read against 144.
240 Hz TestPress Start: the page counts your browser's frames for ten seconds and reads the result against 240 Hz.
AMOLED Grey Uniformity Test for Phones and OLED TVsPress Go full screen, then tap through nine near-black greys and look for patches that stay put.

B–C 9

Backlight Bleed TestDim the room, press Go full screen and look along the edges of the black for light leaking in.
Beige ScreenTap the beige to fill your screen with it, or pick wheat or bisque first.
Black ScreenPress Go full screen to fill your whole screen with pure black, #000000.
Black Smearing Test for MonitorsPress Start and watch the dark block slide over black for a shadow trailing behind it.
Blue Screen TestPress Go full screen and the display turns pure blue, ready for a pixel or night-mode check.
Brown Color Full ScreenPress Go full screen to fill the display with saddle brown, #8B4513, or pick another brown above the button first.
Color Banding TestPress Go full screen and look along the grey ramp for stripes.
CRT Test ScreenPress Go full screen for a checkerboard grid, then step through line patterns, an edge frame and gray steps.
Cyan ScreenPress Go full screen for pure cyan, #00FFFF, or pick light cyan or turquoise first.

D–M 12

Dead Pixel TestPress Go full screen and tap through six colours to check your screen for dead or stuck pixels.
Dual Monitor Image Color TestDrag this window across both screens, or open it on each, and compare the same white side by side.
Full Screen ColorPick a color and press Go full screen for a colored screen from edge to edge, red on arrival.
Ghosting TestPress Start and follow a moving block with your eyes: a fading tail behind it is monitor ghosting.
Gray Uniformity TestPress Go full screen and tap through five flat greys: a shape that stays put may be burn-in.
Green Screen TestPress Go full screen for a pure green field to key out or to check your display.
Monitor Calibration Test ImagesPress Go full screen and step through the test images while you set brightness, contrast and gamma by eye.
Monitor Color TestPress Go full screen and step through the color ladders: every step should look different from the next.
Monitor Flicker TestPress Go full screen on the one-pixel checkerboard, then look closely for shimmer or crawling.
Monitor Gamma TestPress Go full screen, step back until the lines blur, and read the label on the grey square that vanishes.
Monitor Overdrive TestPress Start and watch the edge behind the gray block for a pale halo or a dark shadow.
Monitor Viewing Angle TestPress Go full screen, note which gray square vanishes in each row, then look from the sides, above and below.

O–S 8

Orange ScreenPress Go full screen to fill your screen with orange, or pick a redder or softer orange first.
Pink ScreenPress Go full screen to fill your screen with pink, or pick light or hot pink first.
Projector Calibration Test ScreenPress Go full screen to project a focus grid, then step through an edge frame, dark patches and focus lines.
Purple ScreenPress Go full screen to fill your screen with purple, or pick violet, lilac or lavender first.
Red Screen TestPress Go full screen for pure red, or pick maroon first for a dim red light.
Refresh Rate TestPick your screen's refresh rate, press Start, and this frames per second test counts your browser's frames for ten seconds.
Screen Tearing TestPress Start, go full screen and watch for a break in the moving line.
Stuck Pixel FixerRead the warning, start the square and drag it over the stuck pixel; no fix is promised.

T–Y 7

Teal ScreenPress Go full screen to turn your whole screen teal, or pick dark cyan first.
TV Color Test ScreenOpen this page on the TV, press Go full screen and step through the colour bars.
Ultrawide Monitor TestRead your real pixel count, then press Go full screen for a checkerboard of 21 by 9 squares.
What Is My Screen Resolution?Your screen resolution is the Real pixels figure below, read from this device.
What Sharpness Should My Monitor BePress Go full screen, look close at the thin lines, and lower Sharpness until the gray beside them is flat.
White ScreenPress Go full screen to fill your screen with white, or pick a warmer white first for a soft light.
Yellow ScreenPress Go full screen to fill your screen with yellow, or pick a warmer or paler yellow first.

More about these tools

Plain colours show dead pixels and light bleed, moving shapes show ghosting and tearing, one-pixel grids check 4K, a line chart reads gamma by eye, a frame counter gives the refresh rate and colour bars set up a TV. Used as a display test or an LCD test it has one limit: no online screen tester can measure brightness or colour accuracy, so you judge those by eye. The stuck pixel page is different: a small square that flashes colours rapidly, never full screen, behind a warning. Do not use it if flashing images affect you.

0–9, A 7

B–C 9

D–M 12

O–S 8

T–Y 7

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