Monitor Tester

Use the dead pixel test to display solid color screens (red, green, blue, white, black). Go fullscreen and carefully examine every area of your screen. Dead pixels appear as tiny dots that don't match the background color. Stuck pixels show a constant color, while dead pixels appear black.

The refresh rate test uses requestAnimationFrame to count actual rendered frames per second. For accurate results, ensure your OS display settings match your monitor's native refresh rate (60Hz, 144Hz, 240Hz, etc). Close other tabs and applications for best accuracy.

Dead pixels appear as black dots and are permanently non-functional. Stuck pixels display a constant color (red, green, or blue) and can sometimes be fixed using pixel-cycling videos or gentle pressure. Our color test screens help you identify both types.

The color test displays pure RGB values and gradients. Compare what you see against the expected colors. For professional color accuracy, you'll need a hardware colorimeter, but our test helps identify obvious color shifts, banding, and uniformity issues.

Our response time test uses moving objects to help you visually assess motion blur and ghosting. Lower response times mean less blur. This is a visual test — precise millisecond measurements require specialized hardware like a pursuit camera.

Yes! Open the test on the monitor you want to check and go fullscreen. Works with any display connected to your computer — external monitors, TVs, projectors, and portable displays via HDMI, DisplayPort, USB-C, or VGA.

Display a solid gray or white screen in fullscreen mode. Look for brightness variations across the screen, especially in corners and edges. IPS glow, backlight bleed, and clouding are common uniformity issues visible on solid backgrounds.

Common causes: V-Sync limiting to 60 Hz, browser frame rate caps, power saving mode, incorrect display settings in your OS, or the wrong cable (HDMI 1.4 caps at 60 Hz for 4K). Check Display Settings → Advanced → Refresh Rate. Ensure hardware acceleration is enabled in your browser (Chrome: Settings → System → Use hardware acceleration).

ISO 9241-307 defines pixel fault classes. Class 0 (highest quality) allows zero defects. Most consumer monitors are Class 1 or 2, allowing 1–5 defective pixels. Check your manufacturer's warranty policy — Dell, LG, and ASUS typically replace monitors with 3+ bright dead pixels or 5+ total defective pixels. Document dead pixels with photos for warranty claims.

Stuck pixels (constantly displaying one color) can sometimes be fixed. Try: 1) Run a pixel-cycling video (rapidly flashing colors) on the affected area for 30–60 minutes. 2) Gently apply pressure with a soft cloth on the stuck pixel while cycling colors. 3) Use a pixel-fixing tool that rapidly toggles the affected sub-pixel. Success rate is roughly 50%. Dead pixels (always black) are usually permanent hardware failures.

Backlight bleed is light leaking from the edges of an LCD panel, visible as bright spots or glowing edges on a black screen. Use the dead pixel test's black fullscreen mode in a dark room. Some bleed is normal on IPS panels — it's a manufacturing trade-off for better color and viewing angles. Excessive bleed visible during normal use (dark movie scenes) may warrant a return or warranty claim.

Yes. Move the browser window to the display you want to test, then enter fullscreen. Works with any connection: HDMI, DisplayPort, USB-C/Thunderbolt, VGA. For TVs, ensure the input is set to 'PC mode' or 'Game mode' to disable post-processing that can affect test accuracy.

The gradient test reveals color banding (visible steps between shades instead of smooth transitions), which indicates limited color depth. 6-bit panels show more banding than 8-bit or 10-bit panels. For professional color accuracy measurement, you need a hardware colorimeter (X-Rite, Datacolor). Our test helps identify obvious color issues without specialized equipment.

Yes. It is free with no downloads and no display ads. Monitor tests run locally in your browser, and display information is not sent to any server. Affiliate recommendation events, when present, stay limited to page and offer metadata.