AMOLED Grey Uniformity Test for Phones and OLED TVs

Press Go full screen, then tap through nine near-black greys and look for patches that stay put.

Colour Go full screen, then tap or click for the next one.

What to look for

F goes full screen. Escape leaves.

Near black 4% at level 10

Near black 4% at level 10

#0A0A0A · 0.3 percent of full light

Level 10, still well under half a percent of white's light, and the step the page opens on. Look slowly across the whole width for upright bands, then down the height for sideways ones.

4 of 9

Click, tap or press the right arrow for the next one. The left arrow goes back.

More options
Every

What to look for

What to look for

Doing the check fairly

Next step Single odd dots? Name them on six coloursNow the lighter greys, 5 to 75 percent

How it works

This AMOLED grey uniformity test fills the screen with nine very dark greys, 1 to 20 percent, where OLED panels show their unevenness. Press Go full screen, then tap or click for the next step.

Read the full guide

Why so dark

Each OLED pixel makes its own light, so at the lowest levels small differences between pixels show as blotches, bands or a tint. That is where an OLED grey uniformity check looks. For lighter greys and flat colours, use the gray uniformity test.

Two passes, two brightness settings

Turn automatic brightness off and the room lights down. Run the steps once at your night-time brightness and once at about half: some tints appear only when the screen is turned down low.

  • Read the OLED grayscale steps as a set: a patch that belongs to the panel keeps its place from step to step.

Questions and answers

Is some unevenness normal on an AMOLED screen?

Some, yes, especially on the darkest steps. This page does not grade the panel. Whether a patch is worth a return depends on the seller's or maker's own policy, so read it before you decide.

Why not test on pure black?

An OLED pixel showing black is switched off, so there is nothing to compare. At 1 percent every pixel is lit very dimly, and that is where near-black unevenness shows.

Can I send a screenshot as proof?

No. A screenshot saves the even grey the page sent, not what the panel made of it. Photograph the screen straight on in a dark room, and judge the strength of a patch by eye.

All 18 steps and checks

Near-black steps, 1 to 20 percent 9

  • Near black 1% at level 3 Level 3 of 255, under a tenth of a percent of white's light. The darkest step, where small differences between pixels are easiest to see as blotches or grain. Turn the room lights off before you judge it.
  • Near black 2% at level 5 Level 5. Every pixel should now glow the same faint grey. Patches that are darker, or that look almost black next to lit areas, are the near-black unevenness this test is for.
  • Near black 3% at level 8 Level 8. A green or magenta cast in one area here may be the colour drift of a screen turned down low. Note where it sits, then check whether it is still there at 8 percent.
  • Near black 4% at level 10 Level 10, still well under half a percent of white's light, and the step the page opens on. Look slowly across the whole width for upright bands, then down the height for sideways ones.
Show all 18 steps and checks (14 more)

Near-black steps, 1 to 20 percent, continued

  • Near black 6% at level 15 Level 15, about half a percent of white's light. Patches seen on the darker steps should still be here, and in the same places, if they belong to the panel and not to a reflection.
  • Near black 8% at level 20 Level 20, about 0.7 percent of white's light. A tint seen at 3 percent that has gone by this step is a low-brightness colour shift, not a patch of worn pixels.
  • Near black 12% at level 31 Level 31. Dark scenes in films and games live around here. An area that looks dirty or striped on this step will show in night scenes too.
  • Near black 16% at level 41 Level 41, about 2 percent of white's light. The ghost of a status bar, a navigation bar or an on-screen keyboard left by burn-in can show well on a dark grey like this one.
  • Near black 20% at level 51 Level 51, about 3 percent of white's light, and the last step. Unevenness seen only on the darkest steps may be gone by now; what is still visible here will show in everyday dark scenes.

What to look for 5

  • A green or pink cast at low brightness The colour balance of an OLED can drift as brightness goes down. A tint that shows only with the brightness slider near the bottom, and fades as you raise it, belongs to that drift rather than to worn pixels.
  • Blotches that stay in place Darker or lighter patches that keep their places on the 1 to 4 percent steps. On an OLED each pixel makes its own light, and at the lowest levels small differences between pixels show as patches.
  • The shape of a bar or keyboard A faint copy of something that sat still for hours, such as a status bar or keyboard. On an OLED this is burn-in, uneven wear of the pixels, and it does not fade on its own.
  • Steps that look like pure black If the 1 and 2 percent steps look exactly like a switched-off screen, the darkest shades are being crushed to black. A picture setting or low brightness can cause it; raise brightness a notch and look again.
  • Upright bands across the screen Soft vertical stripes of slightly different brightness that keep their places from step to step. Stripes that move when you move your head are reflections in the glass, not the panel.

Doing the check fairly 4

  • A screenshot cannot show it A screenshot saves the grey the page sent, which is perfectly even, not what the panel made of it. To keep a record, photograph the screen straight on in a dark room with the camera held still.
  • Check at two brightness settings Run the steps once with the brightness where you keep it at night and once at about half. Near-black unevenness on an OLED screen can change with brightness, so one setting can hide what the other shows.
  • Judge by eye, not by the photo A phone camera brightens a near-black field until faint patches look severe. Use a photo as a record of where a patch is, and your eyes for how strong it is.
  • Switch off automatic brightness Automatic brightness changes the screen while you look, and a darker room makes it drop. Turn it off for the test so every step is seen at the same setting.

How this list was compiled: Steps and checks written for this page. Each grey is a share of the full signal of 255, rounded to the nearest level (1 percent is level 3, #030303), and every light figure is relative luminance computed from the sRGB transfer function at https://en.wikipedia.org/wiki/SRGB, with white as 100. That each OLED pixel makes its own light and an unlit one gives none, and that the colour balance of an OLED screen deteriorates as its brightness is lowered by reducing power: https://en.wikipedia.org/wiki/OLED. Burn-in as uneven wear of OLED pixels from a still image: https://en.wikipedia.org/wiki/Screen_burn-in. All read 2026-09-24. That a screenshot holds the image the device sent, not the light the panel gave off, is this page's own explanation. The page names no pass mark and grades nothing: uniformity is judged by eye, and makers set their own limits. Licence: own work

More tests

Show 6 more

Browse Screen and Sound