Rules & quick reference
| Colors | Black, white, red, green, blue, cyan, magenta, yellow |
|---|---|
| Color control | Click or arrow keys; Escape exits fullscreen |
| Refresh estimate | 3 seconds of foreground requestAnimationFrame intervals |
| Interpretation | Visual inspection and browser frame cadence; no automated defect scan |
Inspect the solid-color panel
Select Enter fullscreen to fill the available display with one solid color. Click or press an arrow key to move through black, white, red, green, blue, cyan, magenta and yellow. Escape exits fullscreen using the browser’s normal behavior. During fullscreen the panel removes its text so that labels do not cover pixels you want to inspect. If fullscreen is unavailable, you can still use the embedded panel, although page elements limit the inspected area.
What a color inspection can reveal
A dark point on a bright fill or a bright point on a dark fill may be worth a closer look. Dust, reflections, panel texture, subpixel structure and image retention can resemble defects, so inspect carefully under sensible lighting. The page does not access a camera or read the physical screen back into the browser. It cannot automatically locate dead pixels, count stuck subpixels or repair them. It simply provides predictable full-color surfaces for your own visual inspection.
Estimate the foreground frame cadence
The refresh button collects animation-frame timestamps for three seconds. After discarding initial samples, it calculates the reciprocal of the median valid frame interval. The displayed Hz describes the cadence at which this browser was calling animation callbacks under the current conditions. It is not a direct measurement of the panel’s physical scanout. A browser cap, variable refresh, power saving, a second display or CPU load can affect the estimate.
Compare with the display configuration
Keep the tab visible and let the machine settle before measuring. A hidden tab cancels an active sample because browsers may pause animation callbacks. If the estimate differs from an expected refresh setting, inspect the operating system and display configuration before drawing a hardware conclusion. The tool does not promise a stable rate from one short sample and cannot certify motion response or input lag. Use repeated observations with the same display setup and keep the visual color inspection separate from the timing estimate.
Your result stays on this device
Completed game results are saved in this browser when local storage is available. Bests and recent history describe this device’s saved runs, not a public leaderboard. Changing browsers, clearing site data or using private browsing can remove them. Copy score writes only the visible result summary to your clipboard when you request it; sharing is your choice. Clear local game data removes scores, daily completion markers and the saved 2048 board for this origin. No game result is uploaded, and the games remain usable when persistent storage is unavailable. Use the rule table to check what the active mode measures before comparing another session. A changed duration, input method or grid difficulty can change the task even when the displayed score uses the same unit.
Frequently asked questions
Can this automatically detect a dead pixel?
No. It displays solid colors for visual inspection and cannot read the physical panel.
Can it repair a stuck pixel?
No. The page does not offer a repair or flashing procedure.
Is the Hz number my exact monitor refresh rate?
No. It is an estimate from foreground browser animation-frame intervals.
How do I change colors or exit?
Click or use arrow keys to change colors. Escape exits fullscreen.
Built by Mihai · Reviewed 2026-10-24 · Read the related technical guide · Testing policy