Monitor Test
Ten full-screen test patterns to check a new or used monitor, laptop or TV screen: solid colors and uniformity, gradients and banding, gamma, black and white levels, contrast steps, sharpness and text, color bars and a moving-object test for ghosting.
Solid colors
In full screen: → Space or click for the next variant, ← back, ↑ ↓ change pattern, Esc exit. On touch screens swipe left or right.
How to use the Monitor Test
- Let the monitor warm up for 10 to 15 minutes, set browser zoom to 100% and dim the room lights.
- Pick a pattern from the grid to preview it and read what to look for.
- Press Start full-screen test. Use the right arrow, space or a click for the next variant, up and down to change pattern, and Esc to exit.
- Check each pattern: even colors, smooth gradients, visible dark and light squares, crisp text and clean moving edges.
- Adjust your monitor brightness, contrast, gamma or overdrive settings and run the test again.
What each monitor test pattern checks
| Pattern | Checks | A good screen shows |
|---|---|---|
| Solid colors | Dead and stuck pixels, backlight bleed, tint | Every pixel the same color; no bright edges on black |
| Uniformity | Clouding, vignetting, dirty screen effect | An even shade from center to corners |
| Gradients | Color banding and bit depth | Smooth transitions without visible stripes |
| Gamma | Midtone brightness curve | The 2.2 patch blending into its stripes |
| Black level | Shadow detail, brightness setting | Squares visible from about 2 or 3 on a true black |
| White saturation | Highlight detail, contrast setting | Squares visible up to about 250 to 253 |
| Contrast steps | Tonal separation, color tint | 16 distinct steps per row, neutral grays |
| Sharpness & text | Native resolution, scaling, sharpness setting | Crisp 1 px lines and small text, no halos |
| Color bars | Color, tint and saturation balance | Clean, distinct bars and neutral gray steps |
| Response time | Ghosting, overshoot, motion blur | Clean edges on moving blocks and readable moving text |
How the gamma test is calculated
Each column has a background of alternating black and full-white lines exactly one physical pixel tall, so it emits 50% of the screen's maximum light. The solid patch in the middle is the gray level that a display with gamma γ shows at 50% light: value = 255 × 0.51/γ. That gives 175 for γ 1.8, 180 for 2.0, 186 for 2.2, 191 for 2.4 and 196 for 2.6. When the patch and its stripes look equally bright, that γ matches your display. The test page draws the canvas at your device pixel ratio, so the stripes stay one physical pixel high on high-DPI screens; browser zoom must stay at 100%.
Getting reliable results
- Use the monitor's native resolution and 100% browser zoom; scaling blurs the line and gamma patterns.
- Let the screen warm up for 10 to 15 minutes; brightness and color shift while the backlight warms up.
- Turn off dynamic contrast, eco or energy saving modes, night light, blue light filters and True Tone.
- Check backlight bleed and uniformity in a dark room at your normal brightness, not at maximum.
- Look at the screen straight on at your normal distance; viewing angle changes gamma and contrast, especially on VA and TN panels.
Frequently asked questions
How do I use the gamma test?
Sit back from the screen or squint so the fine black and white lines blur together. The striped background then averages to 50 percent brightness. Find the patch whose solid gray blends best into the stripes; its label is your display's approximate gamma. 2.2 is the standard for Windows, macOS and the web. Browser zoom must be at 100 percent or the lines are resampled and the result is wrong.
What is a good black level result?
On the black level pattern you should be able to see the squares from about 2 or 3 upward against the pure black background. If several of the first squares disappear, raise brightness (or black level) slightly; if the background itself looks gray, it is too high. The white saturation test is the opposite: you should see squares up to about 250 to 253, otherwise lower the contrast.
How do I check for backlight bleed and IPS glow?
Open the black solid color in full screen in a dark room, with brightness at your normal level. Bright patches near the edges or corners that stay in place when you move your head are backlight bleed. A glow that changes or moves as you change your viewing angle is IPS glow, which is normal for IPS panels.
Why do I see bands in the gradient test?
Banding appears as visible steps in what should be a smooth gradient. A little banding is normal on 6-bit and some 8-bit panels, especially in dark shades. Strong banding can be caused by low color depth, aggressive color profiles, night light or blue light filters, or compressed video modes. Disable those features and check the cable and color output settings in your graphics driver.
What does the response time test show?
Blocks and text move across the screen at a constant speed. Faint trails behind them are ghosting from slow pixel transitions; bright or dark halos are overshoot (inverse ghosting) from too much overdrive. Try your monitor's overdrive or response time settings and choose the one with the cleanest edges. Some blur always remains on sample-and-hold displays; higher refresh rates reduce it.
Can this test calibrate my monitor?
It helps you set brightness, contrast and gamma by eye and spot defects, but it cannot measure exact colors. For accurate color work, use a hardware colorimeter with calibration software. Make sure night light, true tone and dynamic contrast are off when checking colors.
Does the monitor test work on phones, laptops and TVs?
Yes. It runs in any modern browser. On iPhone, where web pages cannot enter true full screen, the pattern fills the browser window instead. On TVs, use the browser of the smart TV or cast a laptop screen, and turn off picture enhancements.