Gray Screen

If you could only run one test pattern on a display, it should probably be a mid grey. White exposes dead pixels, black exposes leakage, and grey exposes everything in between , which is where most real panel problems live.

Why mid grey is the most revealing pattern

White and black are extremes, and panels tend to behave predictably at extremes. It is in the middle of the range that manufacturing variation shows: slight differences in how one region of the panel transitions, in how the backlight diffuses behind it, in how the electronics drive one column against the next. A flat grey field gives all of that nowhere to hide.

Uniformity and mura

Look for patches that are slightly lighter or darker than their surroundings, or a faint texture across the surface. These are almost invisible on ordinary content and obvious on flat grey. Move your gaze around rather than staring at one spot , your eye adapts quickly and will normalise a gradient if you let it.

Banding

Grey fields at different levels are the standard way to see banding, where a smooth gradient renders as visible steps. If you notice stepping on this page, try comparing several grey values by typing them into the colour box , #404040, #808080 and #C0C0C0 make a useful set.

Dirty screen effect

Common on larger televisions: faint vertical or horizontal streaks that look like smears on the glass but do not move when you wipe it. Grey is the pattern that shows it, which is why it is the standard field for judging panning shots and sports footage that would otherwise reveal it in motion.

Image retention

A faint ghost of previous content , a taskbar, a channel logo, a game HUD , shows on mid grey more clearly than on any other colour. Persistent shapes on an OLED point towards burn in; shapes that fade after a few minutes of varied content are ordinary temporary retention.

Grey and camera white balance

A neutral grey field looks like a grey card, and the temptation to use one for white balance is understandable. The honest version is more limited.

A grey card works because it reflects the light falling on the scene, so a camera reading it learns the colour of that light. A display emits its own light instead. Pointing a camera at a grey screen tells you the colour temperature of the panel, not of the room, and most displays are nowhere near neutral without calibration.

Where it genuinely helps: setting a consistent reference between two cameras filming the same screen, checking whether a webcam is applying its own automatic colour shift, or giving an exposure meter a flat, predictable surface to read. For matching a subject to room lighting, use a real grey card.

Grey as a working background

• Image editors default to mid grey behind the canvas for a reason: a neutral surround stops surrounding colour from biasing how you judge the image inside it. A grey second monitor does the same job for the rest of your desk.
• It is easier on the eyes than white in a dim room, without going to full black and creating a harsh contrast against a bright primary display.
• As bias lighting behind a monitor or television, a grey screen on a second device raises the ambient level slightly and makes dark scenes more comfortable to watch.

Using and downloading it

1. Press Open fullscreen for a flat field of #808080.
2. Give your eyes a few seconds, then look across the panel in sections rather than at the whole thing.
3. Type other grey values into the colour box to compare levels , banding and retention often show at one level and not another.
4. Press Esc or tap Exit to leave.
5. Choose a size and press Download to keep any of the values you tested.

What this grey screen offers

• Exact #808080 with no gradient, dither or texture
• The most informative single pattern for uniformity, mura and clouding
• Reveals dirty screen effect that neither white nor black will show
• The best field for spotting image retention and early burn in
• Free hex entry so several grey levels can be compared in seconds
• Live preview as the value changes
• One press fullscreen with no interface left on the panel
• PNG, JPG, WebP or SVG export at common presets or any custom pixel size
• Useful as a neutral desktop background or as bias lighting
• Generated in the browser with nothing uploaded
• No account required and no watermark added to generated files
• Keyboard accessible with visible focus outlines
• No web fonts or third party scripts on the page
• Core tools do not require an account

Limits

• A displayed grey is not a substitute for a photographic grey card, for the reason given above: it emits rather than reflects.
• Faint banding can come from the video pipeline rather than the panel , an 8 bit signal, a compression step or a colour management layer. Testing on another device is the quickest way to separate the two.
• Judging uniformity from a phone photograph does not work. Cameras normalise brightness across a frame, which is exactly the thing you are trying to measure.

Related screens

White for dead pixels and dust, black for backlight bleed and lit pixels, and silver for a lighter neutral. Red, green and blue identify which channel a subpixel defect belongs to.

Questions people ask about grey screens