Guides for the parts a test cannot answer.
A tool shows you what your screen does. These guides explain what it means, and what to do about it.
19guides
5topics
38tools they link to
0need an account
Something looks wrong with my screen 5 guides
- ExplainerDead Pixel vs Stuck PixelWhat makers mean by a dark pixel and a bright one, how to tell the two apart in a couple of minutes, and how to rule out dust before you contact support.Links to Dead Pixel Test · Monitor Test · Backlight Bleed Test
- ExplainerHow to Fix a Stuck PixelMake sure it is a stuck pixel, then see what makers say about home fixes, why not to press on the screen, what a pixel-cycling tool can do, and the warranty.Links to Stuck Pixel Fixer
- ExplainerIs Backlight Bleed Normal?Backlight bleed on an LCD, in the makers' own words: why it happens, the lighting Dell and ASUS judge it under, and when yours is worth returning.Links to Backlight Bleed Test · Screen Uniformity Test · Monitor Test
- ExplainerOLED Burn-In: Detect and PreventImage retention versus burn-in on an OLED, how to check your own panel, and the protection features makers build in, quoted from their own support pages.Links to OLED Burn-In Test · Monitor Test · Backlight Bleed Test
- ExplainerScreen Flicker and PWMWhy some screens flicker at low brightness, what PWM and DC dimming are, what "flicker-free" means, and how to check your own screen with a phone camera.Links to Screen Flicker (PWM) Test · Amber Screen
Should I return it, or buy it? 2 guides
- ReferenceDead Pixel Warranty PoliciesWhat Dell, ASUS, LG and Apple publish about pixel faults, quoted with the date each policy was read, and what that means before you return a screen.Links to Dead Pixel Test · Monitor Test
- ReferenceMonitor Buying GuideWhat monitor specifications promise, which ones a browser can check after delivery, and how to use the return window. No models, no prices, no affiliate links.Links to Monitor Test · Refresh Rate Test · Viewing Angle Test · Input Lag Test
Get the picture right 5 guides
- Pillar guideHow to Calibrate a MonitorAn honest guide to adjusting a display by eye with test patterns, what that achieves, and the point where real calibration needs a measuring device.Links to Screen Contrast Test · Gamma Test · Color Accuracy Test · Calibration Pattern (SMPTE bars) · Color Banding / Gradient Test · Sharpness / Text Clarity Test
- ExplainerRefresh Rate ExplainedWhat refresh rate actually changes, how it relates to frame rate, blur, tearing and input lag, and which parts of the chain a browser can and cannot show you.Links to Refresh Rate Test · Motion Blur / UFO Test · Screen Tearing Test · Input Lag Test
- ExplainerHDR ExplainedDisplayHDR 400 against 600 and True Black, quoted from VESA's own published requirements, and what a browser can honestly tell you about your own screen.Links to HDR Test
- ExplainerResolution, PPI and Aspect RatioWhat screen resolution, pixel density (PPI), aspect ratio, CSS pixels and display scaling each mean, and how to work out the numbers for your own screen.Links to Screen Resolution · Aspect Ratio Calculator · PPI / DPI Calculator · Screen Size Calculator
- ExplainerColor Contrast and AccessibilityWhat WCAG's contrast ratios mean: 4.5:1 and 3:1 for text, 7:1 at AAA, 3:1 for controls and graphics, how the ratio is worked out and how to check a pair.Links to WCAG Contrast Checker · Gradient Generator · Palette Generator
Keyboard, mouse, camera and sound 4 guides
- ExplainerThe Mouse Double-Click ProblemWhy a mouse sends two clicks for one press, how to tell a failing switch from a setting, and what the makers tell you to try before replacing it.Links to Double Click Test · Mouse Tester · Click Speed Test (CPS)
- ExplainerKeyboard Keys Not WorkingA key that does nothing, a key that repeats, or keys that vanish when you hold several at once. How to tell which one you have, and what to do about each.Links to Keyboard Tester · Mouse Tester
- ExplainerVideo Call Setup: Camera, Light, MicA practical order for setting up a video call: where the light goes, what the camera is actually sending, and how to tell a muted microphone from a broken one.Links to Webcam Test · Microphone Test
- ExplainerWhite vs Pink vs Brown NoiseWhite, pink and brown noise differ in one thing: how their power is spread across frequencies. What that means, how each sounds, and what research says.Links to White Noise · Pink Noise · Brown Noise
Eyes and comfort 2 guides
- ExplainerEye Strain: Settings That HelpScreen brightness, glare, distance, position, text size and breaks: what the American Optometric Association and other eye-care bodies recommend for screen use.Links to Warm White Screen · Amber Screen · Screen Flicker (PWM) Test
- ExplainerColor Blindness: Types and TestingThe kinds of color vision deficiency, how common each is, what causes it and how an eye doctor tests for it, from the National Eye Institute and MedlinePlus.Links to Color Blindness Simulator
What a guide is for
A test tool can show you a black field, a gradient or a pattern of fine lines. What it cannot tell you is whether a maker would call the result a fault, how many dead pixels a warranty allows, or whether the glow at the corner of your screen is normal for that kind of panel.
That is what these guides are for. Each one answers a question people actually ask, in plain words, and every figure in it comes from a named source with the date it was retrieved. Where no source exists, the guide says so rather than inventing a number.
The Display Diagnostics tools are the place to start — or run the Monitor Test, which walks through the checks in order.