Screen test
Click the pattern to run a full-screen monitor test, then click or press the arrow keys to move through colors, gradients, sharpness lines, and a grid.
Screen test workspace
How to use
4 short steps.
Clean the screen and sit normally
Wipe the screen, sit where you usually sit, and turn off night light or blue-light modes for now.
Click the pattern to go full screen
The first click fills the screen with the black field. Click, tap, swipe, or press Space or the arrow keys for the next pattern.
Look at each pattern for a few seconds
Scan the whole screen on each solid color, then read the one-line instruction under the pattern for what to look for.
Press Escape when you are done
If one pattern looks wrong, open the dead pixel, banding, contrast, uniformity, or ghosting test to check it more closely.
What the result means
Match what you see to one of these.
If a point stays dark or lit on every color, it is a pixel fault
If the same tiny point looks wrong on black, white, red, green, and blue, you have a dead or stuck pixel. Clean the screen first, because dust looks similar.
If the gradient shows steps, something in the chain is losing detail
If the grayscale ramp breaks into bands, the cause can be the display, the cable, a color profile, or the graphics settings. The banding test helps you narrow it down.
If the stripes or grid look uneven, scaling is in the way
If the one-pixel stripes show moire or the grid cells differ in size, browser zoom, system scaling, or the display's own scaling is resampling the image.
Troubleshooting
If the test fails, try these in order.
Set browser zoom to 100%
Press Ctrl+0 or Cmd+0, and set the display to its native resolution in your system settings. Run the sharpness pattern again.
Reseat the cable and remove adapters
Unplug and reconnect the video cable, or try another port or cable. Run the color bars and gradient again.
Change one display setting at a time
Note your brightness, contrast, sharpness, and picture mode, then change one setting and repeat the same pattern.
Try another device
Connect a different laptop or use the display's own test pattern menu. If the fault stays, it is in the display; if it goes, it is in the source.
What this test can't tell you
Where a browser check stops.
- The patterns pass through the browser, operating system, graphics card, cable, and display processing before you see them, so a fault can come from any of those.
- A visual test cannot measure brightness, contrast ratio, color accuracy, response time, flicker, or input lag.
FAQ
Common questions about this test.
How do I run a monitor test?
Open this page, click the pattern to go full screen, and click or press the arrow keys to move through the colors and patterns. Look at each one for a few seconds and press Escape when you finish.
How can I test my screen display?
Use the solid colors to find dead or stuck pixels, the grayscale ramp to find banding, the stripes to check sharpness, and the grid to check geometry. Each pattern shows a one-line note about what to look for.
Does this screen test work on a laptop, phone, or TV?
Yes. It runs in any modern browser. On a phone, tap the pattern to fill the screen and swipe to change it. On a TV, open the page in the TV browser or cast a browser tab.
Can this screen test calibrate my monitor?
No. The patterns help you set brightness, contrast, and sharpness by eye, but calibration needs a colorimeter and software.