Screen & Dead Pixel Tester

Use the five solid colors for visual inspection and compare browser animation timing estimates with system display settings. The browser cannot certify pixel failure, panel refresh rate, PWM flicker or a repair.

Choose a test color

Dead pixel: A point that stays dark on a light background.

Stuck pixel: A point that stays bright on a dark background.

Inspect solid colors and compare browser frame timing

What this guide helps you check

Use five solid colors for a repeatable visual inspection, then compare browser animation timing with your system settings. The page does not repair pixels or calibrate displays.

Before you start

Use the intended display at a comfortable brightness and normal distance. Keep the tab visible for frame timing; close heavy activity for a comparable run. Do not press or rub the screen.

Try it step by step

Use a comfortable brightness and normal viewing distance. Clean the display only as its manufacturer recommends; do not press on the panel.
Choose a color swatch, then Launch Fullscreen Mode. If native fullscreen is unavailable, viewport mode can leave browser controls visible.
Inspect white, black, red, green and blue. Use Next/Previous or the left/right arrow keys while the test surface has focus. Note any point that stays in the same location across colors.
Press Esc or Exit Fullscreen to leave. For frame timing, keep the tab visible and compare several stable intervals with your system display refresh setting.

A persistent dot: compare before concluding

A dark point on white or a bright point on black is an observation to investigate, not proof of a particular transistor failure. Dust, surface marks, image scaling and panel technology can change its appearance.

Check whether the point stays at the same physical location on multiple colors and in another app. Document its position for the manufacturer's pixel/warranty guidance. This tool has no pixel repair mode; do not rub the panel or run intense flashing patterns as a promised fix.

Brightness near edges and viewing angle

Observe black at a comfortable brightness in your normal room, then compare from a centered viewing position. Reflections, panel type, viewing angle and brightness can affect edge brightness and uniformity.

A browser image cannot distinguish manufacturing pressure, backlight leakage or a normal viewing-angle characteristic conclusively. Compare everyday content and the manufacturer's guidance before diagnosing a fault.

What the Hz estimate measures

The rail estimates requestAnimationFrame callback cadence in this browser session. Scheduling, background tabs, power saving, load and variable refresh can alter the estimate. It is not a direct panel refresh readout, pixel response-time test or input-latency measurement.

For example, an estimate near 60 while the system is set to 120 Hz invites checking that this display is selected, the tab is visible and power-saving restrictions are understood. It does not prove that the monitor cannot run at 120 Hz.

What this test cannot establish

A visual inspection cannot certify display condition, color accuracy, HDR behavior or a warranty defect.
The tool does not measure calibrated brightness, physical pixel response or end-to-end input latency. Stop if the colors are uncomfortable.

Two checks, two different signals — **Original conceptual diagram; not a measured hardware result.**Visual inspection Browser frame timing Solid colors: look for visible defects. Frame timing is not panel response time. Illustrative colors and timing; not a test result.

Interpretation example (illustrative)

Illustrative example: a point remaining dark on white, red and green in the same physical location merits a comparison in another app and the manufacturer’s pixel guidance. A single dark point is not a transistor diagnosis.