Screen & Monitor Test

A dead pixel gets no power and stays black on every color, so it shows up on white or bright solids. A stuck pixel has one or more subpixels locked on, so it stays red, green, blue or a mix and is easiest to spot on black. Stuck pixels can sometimes be revived with the stuck pixel fixer, dead pixels cannot.

Sometimes. Rapidly cycling colors over a stuck subpixel can free it, and it is the standard first thing to try before a return or RMA. Run the patch over the pixel for 10 to 20 minutes. It will not revive a dead (always black) pixel and it is not guaranteed. The pattern flashes, so skip it if you are sensitive to flashing light.

No. Backlight bleed is light leaking around the panel edges, it stays in the same place when you move your head. IPS glow is a silvery sheen seen at an angle and it shifts or fades as you change your viewing position. Judge both on full black in a dim room, from your normal seating distance, as the backlight bleed test walks you through.

No, and no browser test can. The browser canvas and compositor work at 8 bits per channel in practice, so the banding test shows 256 equal steps. A good panel shows them evenly; a weak panel, FRC or a color profile shows uneven jumps, crushed blacks or a tint. That tells you about processing quality, not panel bit depth.

It times how often this browser paints frames on the screen the window is on. The median frame interval gives a first estimate, then the total time is divided by the number of refresh cycles it spans, so the result stays exact even though browsers round frame timestamps. That matches the display refresh rate in most setups. Battery saver, some browsers and some devices cap the rate, and a window on a second monitor may follow the primary one; the result then shows that limit, not the panel maximum.

The readout shows the device pixel grid the browser draws into: screen size in CSS pixels times the device pixel ratio. On Windows and Linux, and at 100% browser zoom or any zoom level, that is the native resolution. On a Mac with a scaled "looks like" setting, macOS renders at a larger size and scales it down, so the grid is bigger than the panel. Pick the default or native setting to test pixel by pixel.

Safari on iPhone does not allow web pages to go truly full screen. The test fills the whole visible area and hides all controls instead; rotate to landscape, or add the page to your Home Screen, to get the most of the panel in view. iPad and Android support real full screen.

Not from a browser. PWM dimming happens below the level a web page can see; a phone camera in slow-motion or pro mode pointed at the screen is the usual workaround. Subpixels can only be seen with a magnifier or a macro lens, any on-screen zoom would just enlarge our own rendering.

No. Every pattern is drawn locally in your browser, and the inspection report is built and downloaded on your device. Nothing about your screen or your results leaves the browser, and no account is needed.