Screen Test
Enter fullscreen and cycle solid colors, gradients, and grids to find dead pixels quickly.
Screen Test
Cycle through patterns for dead pixel and color uniformity checks.
Select Pattern
All Patterns
Keyboard Shortcuts
Testing Tips
- • Use solid colors to check for dead or stuck pixels
- • Use white to check for backlight uniformity
- • Use grayscale gradient to check for color banding
- • Use checker pattern to check for response time and ghosting
How this test works
We render solid colors, gradients, and grids in the browser and optionally enter fullscreen so you can scan for tinting or pixel defects. Nothing is downloaded or stored.
- • Fullscreen hides UI chrome so you can scan edges and corners.
- • Patterns are generated locally; reload to reset the sequence.
Troubleshooting
- • Turn off Night Light, True Tone, or f.lux while testing to avoid color shifts.
- • Set brightness to a comfortable mid-to-high level so defects are visible.
- • Use the display's native resolution and a quality cable for external monitors.
- • If fullscreen fails, allow fullscreen permissions for this site or try another browser.
Quick steps
- • Enter fullscreen, then cycle solid colors to spot dead or stuck pixels.
- • Use the grid pattern to check for uniformity or distortion.
- • Toggle gradients to look for banding or severe tinting.
- • Switch to a neutral grey to find stains or uneven backlight.
Check for dead or stuck pixels
- • Keep a solid red, green, blue, white, then black screen and scan slowly edge to edge.
- • A stuck pixel shows as a bright dot on some colors; a dead pixel stays black on all colors.
- • If you see one, note its position before contacting the display vendor about warranties.
- • Gently massaging around a stuck pixel may help; do not apply force on a glass panel.
If colors look off
- • Disable blue-light filters and auto-brightness while testing.
- • Check display cables and ports for secure connections.
- • Reset any aggressive color profiles or GPU enhancers, then retry.
- • On laptops, switch off battery saver to avoid dimmed panels.
Check refresh rate
- • Windows: Settings > System > Display > Advanced display to view and select the refresh rate.
- • macOS: System Settings > Displays > Refresh Rate to pick the highest supported value.
- • Match the refresh rate to your GPU output and cable limits (HDMI vs DisplayPort).
- • If motion looks jittery, try a higher rate or disable variable refresh during testing.
External monitor checklist
- • Use the cable that supports your target resolution and refresh (DisplayPort or HDMI 2.0+ for 4K 60).
- • Confirm the source is set to native resolution in the OS; avoid scaled modes while inspecting pixels.
- • If the screen stays black, power-cycle the monitor and reselect the input source.
Calibrate quickly
- • Set brightness until white is bright but not glaring; avoid clipping detail in near-white gradients.
- • Adjust contrast until black squares on the grid remain distinct without crushing.
- • Use the neutral grey to spot color cast; tweak temperature toward neutral.
Reduce color banding
- • Check that your OS is outputting at 8-bit or higher to the display.
- • Disable forced HDR if gradients show harsh steps in a dim room.
- • Close GPU overlay apps that inject filters or sharpening.
- • Try a different cable or port if gradients look posterized at higher refresh rates.
Laptop panel care
- • Clean the screen with a soft microfiber cloth and a small amount of screen-safe cleaner.
- • Avoid pressing on the panel; pressure can create temporary bright spots.
- • Keep vents clear so heat does not cause temporary discoloration.
When to use this test
- • After buying or transporting a monitor or laptop to confirm the panel is clean.
- • Before creative work where color accuracy matters.
- • When you spot discoloration or faint lines and want to isolate the source.
- • Before selling a device to document panel condition with screenshots of the patterns.
If fullscreen is denied
- • Click the fullscreen button again and approve the prompt if the browser asks.
- • Check browser site settings and allow fullscreen for this page.
- • Try another browser profile without extensions that block fullscreen.
Safety and privacy
- • All patterns render in your browser; no images are fetched or uploaded.
- • Exit fullscreen anytime with Esc if you share the screen during calls.
- • Use a private window if you do not want fullscreen permission remembered.
Related tools
Browser Capability Test
Confirm fullscreen and graphics APIs are available.
Mouse Test
Check pointer movement and buttons on the same hardware.
Webcam Test
Verify your camera if you're evaluating overall device condition.
Pre-Call Checklist
Make sure your display and other devices are ready before meetings.
FAQ
Is fullscreen safe and how do I exit?
Yes. Press Esc or tap the exit control to leave fullscreen at any time.
Can this fix dead pixels?
No. The test helps you spot dead or stuck pixels. Pixel-flashing loops sometimes revive stuck pixels, but results vary.
Why do colors look tinted?
Night Light, True Tone, f.lux, or low brightness can tint the display. Turn them off to judge colors accurately.
Can this show refresh rate?
Refresh rate comes from your OS or monitor OSD. Use this test to look for tearing or stutter that hints at a low rate.
Does HDR change the results?
HDR can lift highlights and dim the UI. Toggle HDR off if the patterns look washed out while you inspect colors.