The standard behind the thresholds
ISO 9241-307, which replaced ISO 13406-2, groups displays into pixel fault classes. Each class sets a maximum number of faults per million pixels, split into three types: a pixel that is always on, a pixel that is always off, and individual sub-pixels that are stuck.
Class II is the one that matters to most people, because it is what consumer monitors, laptops and televisions are typically built to. Working from the per-million figures, a 1920 by 1080 panel has roughly 2.07 million pixels, so a Class II panel of that size is allowed on the order of four always-on or always-off pixels before it fails the standard.
The dead pixel test page carries the full class table with those figures. What that table cannot tell you is your case, for one important reason explained next.
The standard is not your warranty
This is the part that catches people out. ISO 9241-307 describes classes; it does not oblige any manufacturer to honour any of them. Your rights come from the warranty your manufacturer published for your model, plus consumer law in your country.
In practice manufacturers write their own pixel policy, often referencing a class, sometimes setting their own count, and sometimes distinguishing between bright pixels (always on, far more visible on a dark screen) and dark pixels. Some premium and professional monitors carry an explicit zero-bright-pixel guarantee, which is a real differentiator and is worth looking for when buying.
We deliberately do not publish a table of thresholds per manufacturer here. Those policies change, differ by region and differ by product line, and a stale table in a guide is worse than no table when someone is about to file a claim. Find your manufacturer's own pixel policy page for your model, note the date you read it, and work from that.
Finding your policy
- Identify the exact model number, from the label on the back of the monitor or from your system information on a laptop. Product lines differ from each other more than brands do.
- Search the manufacturer's own support site for their pixel policy or dead pixel policy. Avoid third-party summaries, including this one, as your source of record.
- Note whether the policy distinguishes bright pixels from dark pixels, and whether it counts sub-pixels separately. Those distinctions decide most borderline cases.
- Check the warranty period and whether pixel defects have their own, shorter period. Some do.
- Check your consumer rights separately. In several jurisdictions statutory rights around goods being fit for purpose sit alongside the manufacturer's policy rather than being replaced by it.
Documenting what you found
A claim needs three things: proof of purchase, the serial number, and evidence of the fault. The first two you have. The third is where the dead pixel test earns its place.
Run the test full screen and cycle through the solid colours. A dead pixel shows as a black dot on every colour. A stuck pixel shows as a coloured dot that stays the same colour on every background. Note how many you find and on which colours they appear, because that distinction is exactly what the policy classifies.
Photograph the screen with the relevant colour displayed, close enough that the pixel is visible in the photograph. Then save or copy the test result so you have a dated record of what you ran and when.
Do this before you contact support, not during. A claim that opens with a count, a photograph and a date is triaged differently from one that opens with a description.
Dust, dead and stuck are three different things
| What you see | On a white screen | On a black screen | Test |
|---|---|---|---|
| Dust or a mark on the surface | Visible | Usually visible | It moves or disappears when you wipe the screen with a microfibre cloth |
| Dead pixel (always off) | A black dot | Invisible, because the surroundings are black too | Stays black on every colour, and wiping changes nothing |
| Stuck pixel (always on) | Often invisible | A bright coloured dot | Stays the same colour on every background |
Compiled by MyGearCheck. The wipe test is worth doing first every time: a surprising share of reported dead pixels are specks of dust, and it costs ten seconds to rule out.
Can a stuck pixel be fixed?
Sometimes, and only a stuck one. A stuck pixel is a sub-pixel locked in one state, and rapidly cycling colours over that area occasionally frees it. Gentle pressure over the pixel while cycling is the other commonly described method.
Be honest about the odds and the risk. This works some of the time on some panels, and it is a prediction rather than a procedure with a known success rate: we have not measured one and neither has anyone publishing a number you can trust. Pressing on an LCD too hard can create a permanent bright spot, which turns a small problem into a larger one.
A dead pixel, one that is always off, does not respond to this. The sub-pixel is not receiving power or the transistor has failed, and no amount of colour cycling changes that.
Frequently asked questions
How many dead pixels are acceptable before a screen counts as faulty?
It depends on the pixel fault class your panel was built to and on your manufacturer's own policy. Under ISO 9241-307, a Class II panel, which covers most consumer displays, allows two always-on and two always-off pixels per million, so roughly four in total on a 1920 by 1080 screen. Your manufacturer's published policy is what decides your claim.
Is a dead pixel covered by warranty?
Only if the number and type of defects exceed the threshold in the manufacturer's pixel policy for your model. One dead pixel almost never qualifies on a consumer display. Panels sold with an explicit zero-bright-pixel guarantee are the exception.
What is the difference between a dead pixel and a stuck pixel?
A dead pixel is always off and shows as a black dot on a white background. A stuck pixel is always on and shows as a coloured dot on a black background. Stuck pixels sometimes respond to colour cycling; dead pixels do not.
Does the dead pixel test detect pixels automatically?
No, and no browser test can. It fills your screen with pure colours so a defect stands out, and the judgement is yours. Anything claiming to detect dead pixels automatically cannot see your screen.
Why does my screen look fine in the shop and show pixels at home?
Shop lighting hides almost everything. Solid black and solid white fields in a dim room are the conditions that reveal both dead pixels and backlight bleed, which is exactly why a demonstration floor never shows them.
Can a night light or colour profile affect the test?
Yes. An operating-system night light, a colour profile or HDR tone mapping sits between the page and the panel, so what you see may not be the exact value the page requested. Turn those off before judging a display.
Do dead pixels spread?
A single failed transistor does not propagate to its neighbours. What can happen is that a panel with a manufacturing weakness develops more defects over time, which looks like spreading. If new pixels appear over weeks, document each one, because a growing count changes a borderline claim.
Is a zero-bright-pixel warranty worth paying for?
It depends entirely on what you do. On a monitor used for photography, video or long text work on light backgrounds, a single bright pixel is genuinely distracting and the guarantee removes the lottery. For general use, most people stop noticing one within a week.