What goes wrong in this category
Display faults divide neatly into two kinds, and the split decides what you should do about them. Point defects are individual pixels stuck on or off, which are a manufacturing lottery and are covered, or not, by a threshold in your manufacturer's pixel policy. Field defects are backlight bleed, uniformity patches and banding, which affect an area rather than a point and are almost never covered at all.
Both need conditions rather than instruments. A solid black field in a dark room shows backlight bleed and stuck pixels, and shows neither in daylight. A solid white field shows dead pixels and uniformity. A grey gradient shows banding, which more often comes from the cable or the negotiated colour depth than from the panel. This is why a monitor on a bright shop floor always looks flawless and the same monitor at home does not.
Neither test on this page measures anything. They put an exact colour or pattern on your screen and the judgement is yours. That is also why anything claiming automatic dead-pixel detection cannot be doing what it says: a web page cannot see your screen. What these tests can do is remove every variable except the panel, which is most of the work.
Which test for which symptom
| Symptom | Test | What it tells you |
|---|---|---|
| A dot on the screen that will not wipe off | Dead Pixel Test | Whether it is dust, a dead pixel or a stuck pixel, which decides whether a claim is worth filing |
| Light leaking from the edges in dark scenes | Monitor Test | Backlight bleed on a solid black field, judged at the brightness you actually use |
| Visible steps in a smooth gradient | Monitor Test | Colour banding, which more often comes from the cable or colour depth than from the panel |
| Text or lines look soft or shimmery | Monitor Test | Whether a one-pixel grid renders cleanly, which exposes scaling and sharpness processing |
| Patchy brightness on a white background | Monitor Test | A uniformity fault, which does not improve and cannot be calibrated away |
Compiled by MyGearCheck. The last column is deliberately bounded: these tests observe what reaches the browser, which is enough to separate hardware from software and not enough to name a failing component.
Guides for display
A test tells you what is happening. These explain what to do about it, including when the honest answer is that nothing is wrong.