Free Online Display Test
Free Screen Colour Test
Test solid colours, greyscale, gradients, black levels, white saturation and display contrast in fullscreen.
Works on compatible monitors, laptops, tablets and mobile devices. No browser permission is required.
Check Screen Colours and Uniformity
Choose a pattern or open fullscreen mode and move through every visual check using the on-screen controls or keyboard.
Visual test only
This tool can reveal obvious colour, uniformity and banding problems, but professional calibration requires a hardware colourimeter.
Screen Colour Patterns
The test includes 16 visual checks covering solid colours, gradients, colour bars, black level, white saturation, contrast and a custom colour.
| Pattern | What to inspect |
|---|---|
| White | Check for dim areas, colour tinting and uneven brightness. |
| Black | Check black uniformity, backlight bleed and bright pixels. |
| Red | Check red-channel consistency and colour contamination. |
| Green | Check green-channel consistency and stuck subpixels. |
| Blue | Check blue-channel consistency and colour uniformity. |
| Cyan | Check combined green and blue output. |
| Magenta | Check combined red and blue output. |
| Yellow | Check combined red and green output. |
| Mid Grey | Check neutral balance, tinting and panel uniformity. |
| Greyscale Gradient | Look for smooth transitions without visible bands or sudden jumps. |
| Colour Gradient | Check colour transitions, banding and abrupt hue changes. |
| Colour Bars | Compare primary and secondary colours at equal intensity. |
| Black Level | Check whether near-black steps remain distinguishable from pure black. |
| White Saturation | Check whether very bright shades remain distinguishable from pure white. |
| Contrast Pattern | Check edge clarity and whether black and white areas remain distinct. |
| Custom Colour | Choose any colour for a custom full-screen inspection. |
Choose Any Screen Colour
Select a colour or enter a six-digit hexadecimal value, then open that colour fullscreen for inspection.
Screen Information
The live tool also reports screen size, viewport, pixel ratio, colour depth, orientation and fullscreen support.
Fullscreen keyboard controls
- Left and Right arrows — change pattern.
- Space — hide or show fullscreen controls.
- Escape — exit fullscreen.
No Screen Content Is Captured
The page displays browser-generated colours and patterns. It does not record, photograph or upload your screen.
How to Use the Screen Colour Test
- Clean the display and reduce reflections.
- Set brightness to a comfortable normal level.
- Open fullscreen mode.
- Inspect every solid colour for uneven patches or pixels.
- Check gradients for visible bands or sudden changes.
- Use black and white level patterns to assess contrast.
What to Look For
Watch for colour tinting, dark corners, bright patches, backlight bleed, image retention, banding and pixels that remain a different colour from the surrounding area.
View the display straight on. Many panels naturally change colour or brightness when viewed from an angle.
What the Online Screen Colour Test Checks
The fullscreen patterns help you inspect colour channels, panel uniformity, gradients, contrast, shadow detail and highlight detail. Each pattern isolates a different part of the display so visible faults are easier to identify.
Solid colour uniformity
White, black, red, green, blue, cyan, magenta, yellow and grey screens make uneven brightness, colour patches and pixel defects easier to see.
Dead and stuck pixels
A pixel that remains dark, bright or the wrong colour may stand out against one or more fullscreen solid backgrounds.
Greyscale banding
The black-to-white gradient helps reveal visible steps, posterisation or abrupt transitions instead of a smooth tonal change.
Colour-gradient transitions
The multi-colour gradient helps identify banding, clipped hues and sudden colour changes across the visible spectrum.
Black and white levels
Near-black and near-white tiles show whether shadow detail or bright highlight detail is being crushed into a single tone.
Contrast and edge clarity
High-contrast checks make blurred edges, scaling artefacts, ringing and poor separation between black and white easier to notice.
Screen Colour Test Patterns Explained
Use the patterns in a dim, reflection-free room at a normal viewing distance. Inspect the entire panel, including corners and edges, rather than focusing only on the centre.
White screen
Look for yellow, blue, pink or green tinting, darker corners, cloudy patches and uneven brightness.
Black screen
Inspect for backlight bleed, IPS glow, bright pixels, edge light leakage and uneven black levels.
Red, green and blue
Primary colours isolate individual subpixel channels and can reveal dead, stuck or contaminated pixels.
Cyan, magenta and yellow
Secondary colours combine two channels and help expose inconsistent colour mixing or channel imbalance.
Mid-grey screen
Grey is useful for spotting white-balance tint, dirty-screen effect, image retention and subtle uniformity variation.
Greyscale gradient
A healthy result should transition gradually from black to white without obvious stripes, jumps or missing tones.
Colour gradient
Check that hue changes are continuous and that no section shows unexpected desaturation, clipping or abrupt boundaries.
Colour bars
Compare equal-intensity colour blocks for consistent brightness, saturation and clean boundaries.
Black-level pattern
The darkest numbered tiles should remain subtly distinguishable when brightness and black level are configured correctly.
White-saturation pattern
The brightest numbered tiles should remain distinguishable instead of merging completely into pure white.
Contrast pattern
Inspect sharp black-and-white edges for scaling softness, halos, ringing or excessive display sharpening.
Custom colour
Enter a precise hexadecimal colour to inspect a specific tone used in design, photography, gaming or product work.
Screen Problems the Test May Reveal
A visual browser test cannot identify the internal cause of a fault, but it can help you document repeatable symptoms before changing settings, replacing a cable or requesting a repair.
Uneven brightness
One area appears consistently darker or brighter than the rest of the panel, especially on white or grey.
Colour tint or white-balance shift
Neutral white or grey appears noticeably blue, yellow, pink or green across part or all of the screen.
Backlight bleed and glow
Bright patches are visible near the edges or corners of an LCD when displaying a dark screen.
Colour banding
Gradients show visible stripes or blocks instead of smooth transitions between neighbouring shades.
Black crush
Several near-black shades merge into pure black, causing shadow detail to disappear.
White clipping
Several near-white shades merge into pure white, removing highlight detail.
Image retention
A faint trace of previous content remains visible on a neutral grey or solid-colour background.
Dead or stuck pixels
Individual pixels remain black, bright or fixed to a particular colour while surrounding pixels change normally.
When to Use a Screen Colour Tester
Run the test whenever you need a repeatable visual check of a monitor, laptop, television, tablet or phone display.
After buying a new display
Check the panel during the retailer's return period for obvious uniformity, pixel, banding or backlight issues.
After changing display settings
Compare colour modes, brightness, contrast, HDR, night-light and enhancement settings using the same patterns.
Before creative or colour-sensitive work
Look for obvious tinting, clipping and gradient problems before editing photographs, video, graphics or web designs.
Before selling or repairing a device
Document repeatable screen symptoms and compare results with another cable, source device or display.
How Accurate Is an Online Screen Colour Test?
The browser can display precise digital colours and gradients, making this tool useful for visual comparison. What you actually see still depends on the panel, browser colour management, graphics output, operating-system profile, display mode, viewing angle and ambient light.
Repeat observations under the same conditions. A problem that appears in several patterns and remains visible after changing the source or cable is more likely to be display-related.
What This Test Cannot Measure
It cannot calculate colour accuracy, Delta E, gamma, colour temperature, gamut coverage, luminance, contrast ratio or HDR peak brightness with laboratory accuracy.
Reliable calibration and measurement require a compatible colourimeter or spectrophotometer, calibration software and controlled lighting.
What Screen Colour Results Mean
Solid colours help reveal pixel defects and uneven panel output. Gradients help reveal banding, while near-black and near-white steps show whether shadow and highlight detail is being clipped.
Some variation is normal on consumer displays. Compare results at normal brightness and with manufacturer colour-enhancement modes disabled when possible.
Screen Colours Look Incorrect?
Try these checks before assuming the panel is faulty.
Reset display settings
Disable unusual colour filters, night modes and enhancement presets, then repeat the test.
Check the cable and port
Reconnect external displays and try a compatible cable or another graphics port.
Update graphics drivers
Driver problems can affect colour depth, range and display output modes.
Compare another device
Connect the display to another computer or compare with another monitor to isolate the source.
Frequently Asked Questions
Is this screen colour test free?
Yes. It is free and requires no account, download or permission.
Can this calibrate my monitor?
No. It provides visual test patterns. Accurate calibration requires a supported hardware colourimeter and calibration software.
What causes colour banding?
Banding can be caused by limited colour depth, compression, graphics settings, panel limitations or image-processing modes.
Why does grey look slightly coloured?
A colour tint can come from white-balance settings, panel uniformity, viewing angle, ambient lighting or colour-profile configuration.
Should black appear completely black?
OLED panels can display very deep black. LCD panels may show some glow because they use a backlight.
Can this detect dead pixels?
Solid colours can help reveal dead or stuck pixels, but the dedicated dead-pixel test provides a more focused workflow.
What is the best colour for finding dead pixels?
Use several solid backgrounds. White, black, red, green and blue are especially useful because different pixel and subpixel faults appear against different colours.
How do I test screen uniformity?
Open white, grey and black fullscreen patterns and compare the centre, edges and corners for consistent brightness and colour.
What is backlight bleed?
Backlight bleed is visible light leakage near the edges or corners of an LCD panel, most noticeable on dark content in a dim room.
What is IPS glow?
IPS glow is an angle-dependent brightening often seen near the corners of IPS-type LCD panels. Its appearance changes with viewing position and distance.
How do I check black crush?
Use the black-level pattern. Several near-black tiles should remain subtly distinguishable instead of merging into one black area.
How do I check white clipping?
Use the white-saturation pattern. The brightest steps should remain distinguishable instead of disappearing into pure white.
Can this screen test check HDR?
The patterns can reveal obvious clipping or tone differences, but the page cannot verify HDR certification, peak brightness, tone mapping or colour-volume performance.
Can I use this test on a phone or tablet?
Yes. Fullscreen support and browser controls vary by device, but the solid colours and gradients can still be used for visual inspection.
Why do colours change when I move my head?
Many display panels shift in brightness, contrast or colour when viewed off-axis. Test from your normal centred viewing position.
Should I disable night mode before testing?
Yes. Disable night light, blue-light filters, colour filters and unusual enhancement modes when you want to inspect the display's normal colour output.
Related Display Tests
- Dead Pixel Test — Inspect the screen using fullscreen solid colours.
- Screen Resolution Test — Check screen dimensions, viewport and pixel ratio.
- Refresh Rate Test — Measure browser FPS, frame time and motion smoothness.
Run the Complete Device Check
Continue with resolution, refresh rate, pixels, camera, audio and input diagnostics.