🎮Controller and screen tests

A stick at rest should report values hovering within a few hundredths of zero. Movement past that with your hands off the controller is drift, and once it is large enough to move a camera or a cursor on its own, it will not settle down again — potentiometer wear is one-directional. The drift test turns the resting deviation into a score so you can compare the same stick a month apart instead of relying on how it felt last time.

A deadzone is the game’s answer to drift: it ignores small stick values so a slightly worn stick still behaves. That is why a controller can be visibly drifting here and feel fine in one game and unplayable in another — the games are applying different deadzones to the same signal. This test deliberately applies none, which is the only way to see what the hardware is really sending.

The colour tells you. A pixel that stays black on a white screen is dead — its transistor has failed and there is nothing to revive. A pixel showing a fixed red, green, blue or white dot on a black screen is stuck: the subpixel is jammed on rather than broken off. Run the test twice, once on white and once on black, and the difference is obvious.

Sometimes, and the odds are better the newer the fault. Cycling colours rapidly over the area exercises the subpixel and occasionally frees it, which is why this site includes a cycling mode; leave it running for a quarter of an hour or so. It does nothing for a genuinely dead pixel, and there is no software that can — that one is a panel replacement or nothing.

Because the browser measures the frames it was actually handed, and something upstream is capping them. The usual causes are a cable or port limited to 60 Hz at your resolution, a display setting still on the default rate, browser hardware acceleration switched off, or a laptop on battery in a power-saving mode. Change one at a time and re-run — the reading is the fastest way to find out which one it was.

Because they are two different measurements. The browser reports CSS pixels, and your operating system’s scaling multiplies them: at a device pixel ratio of 2 a 2,560-pixel-wide panel reports 1,280 to the page. Neither figure is wrong, which is why both are shown side by side along with the ratio between them, and the physical width is the two multiplied together.