PanelPeek
PanelPeek → How to test a new monitor
How to test a new monitor
A new display deserves a quick, careful look before the return window closes. PanelPeek gives you the patterns for free in the browser; this guide explains how to run them in a useful order and what a sensible observation record includes. Everything here is a manual visual check: the tool does not detect defects for you.
Before you start
- If you can, let the display warm up for around 30 minutes first, and clean the screen gently; dust and fingerprints are often mistaken for pixel faults.
- Move the browser window to the display you are checking, remove any scaling you did not intend to use, and sit at your normal viewing distance.
- Use dim, comfortable room light for the black and grey steps, and your usual brightness setting instead of maximum.
- Turn off power-saving dimming or automatic brightness if the screen supports it, so the patterns stay steady.
- Full screen needs a click from you and browser support. If it is unavailable or you decline it, only the browser-visible area is checked, and physical edges outside the window are not tested.
Step 1 — solid colours for pixel faults
Open the test and move through red, green, blue, white and black full-screen colours. Look for a dot that never changes: a dark dot on every colour is usually a dead pixel, while a dot stuck on one colour can look normal on some patterns and obvious on others. Clean the screen before you judge a single dark speck — it may simply be dust.
Step 2 — black and grey steps for backlight and uniformity
On a black screen, check the edges and corners for light patches. IPS glow changes with your viewing angle and distance, while backlight bleed stays roughly in place as you move; the two are often confused. Grey steps help you see whether one area is brighter or darker than the rest. This is an observation aid, not an automatic diagnosis.
If your screen is OLED, "backlight bleed" does not apply because there is no backlight; you can still note brightness uniformity and any colour shifts.
Step 3 — grid and text for sharpness and scaling
A grid and sample text show whether the image is crisp at native resolution, whether text is rendered cleanly and whether scaling makes thin lines look soft. Confirm the display is running at its native resolution in the operating system first; a scaled desktop can make a perfectly good panel look blurry. The grid and text are CSS lines and rendered text, not a one-to-one physical pixel ruler, so treat them as a sharpness impression rather than a pixel measurement.
Step 4 — record what you observed
The checklist has four groups: Pixels & bright dots, Dark-screen glow, Gray & uniformity, and Grid & text clarity. Mark each group as Not checked, Nothing noticed or Issue noticed, and attach short notes to the group they belong to. Export the checklist as JSON or text, or print it, and keep the copy with your order or receipt.
What this check can and cannot prove
It records your visual observations at one moment and one brightness setting. A screenshot cannot prove a physical panel defect, and many sellers ask for their own inspection. A few dark or bright pixels may fall inside the pixel policy of the specific model, which differs between manufacturers and product lines. Keep the observation record and contact the seller or manufacturer for a warranty decision.
Short FAQ
Is a dead pixel always black?
A dead-pixel observation is a persistent dark spot on light patterns such as white and the solid colours; a stuck-pixel observation is a persistent bright or coloured spot that is easiest to see on dark patterns. A single pattern is not enough to classify the fault, so compare white, black and the solid colours before writing a note; pixel and sub-pixel structures vary between panels.
Does running this test repair anything?
No. PanelPeek only shows patterns and records your notes, and it deliberately does not flash colours or run pixel-repair routines.
Can I use phone photos as evidence?
Photos may help you compare the screen over time, but a photo of a screen is not proof of a panel defect on its own; use the seller's or manufacturer's inspection process for a claim.
References
Short background used for this guide; the checks above are our own operating steps:
- Dell display pixel guidelines — bright and dark pixel faults, sub-pixels, and pixel policy differing by model; it does not recommend pressing the panel or software repair.
- Dell: IPS glow and light leakage — glow varies with angle and distance, while light leakage is relatively fixed.
- EIZO Monitor Test — warm up the monitor, follow manufacturer specifications and observe each test item manually.