Monitor test
Ten checks in a sensible order, with a verdict you record yourself at each step and a summary you can keep.
Step 1 of 10
White field
Dust and smears on the glass, black dots that are dead pixels, a colour cast across the whole screen, and corners that are dimmer than the middle.
Wipe the screen first. A speck of dust is the most common false alarm there is.
Esc to exit · arrow keys to change · H hides the controls
Your results
These are the verdicts you recorded, not measurements. Nothing was detected automatically, and the summary says so wherever you send it.
How the guided check works
- Work through the ten checks in order. Each one tells you what to look for before you start it.
- Press Show to put the pattern on screen. Press Esc to come back and record what you saw.
- Mark each check as fine, a problem, or not sure. Nothing is detected for you, the verdict is yours.
- Your answers are saved in this browser only, so you can stop and come back without losing them.
- At the end, copy or download the summary. It is plain text, suitable for a support ticket or a second-hand listing.
What a problem looks like
- Several checks fail at once
- Before blaming the panel, check the cable and the input. A marginal HDMI or DisplayPort connection can produce banding, wrong colour range and a capped refresh rate simultaneously, and swapping the cable is free.
- Everything passes but the screen still looks wrong
- Look at your colour profile and your display picture mode. A vivid or dynamic preset will pass every one of these checks while making ordinary content look oversaturated and harsh.
- One check fails badly
- Go to that tool page directly. Each one explains the specific fault in more depth, lists the usual causes, and tells you which of them you can fix from a settings menu.
- The display is second-hand and several checks are marginal
- Marginal results matter more on a used display, because you have no return window. Burn-in, uniformity and dead pixels are the three that do not improve with time.
What to do next
If something looks wrong, check it again in a normally lit room and from straight on, then check whether it appears on a second device. If it only happens on this screen and you are still inside the return window, that is the time to contact the retailer.
Questions people actually ask
How long does this take?
About five minutes if you move briskly, or fifteen if you are checking a new display carefully before the return window closes. The near-black step benefits from letting your eyes adapt for a minute, which is the slowest part.
Does it save my results?
In your own browser, yes, so you can stop and come back. Nothing is uploaded, because there is no server to upload to. Clearing your browser data clears the results.
Can I use this on a phone or a television?
Yes. The checks are the same, though a television is best judged from your normal seating distance rather than close up, and a phone benefits from turning off auto-brightness and any warm-light feature first.
What should I do if a check fails?
Follow the link on that step to the dedicated tool, which explains the fault properly and lists the usual causes. Many failures here are settings rather than hardware, particularly the near-black and refresh rate checks.
Is this a substitute for a professional calibration?
No. It finds faults and misconfiguration, which is what most people actually need. Calibration means measuring your display with a colorimeter and building a correction profile, and nothing in a browser can do that.