Compare one field across the whole screen
Start with Mid gray and sit directly in front of the display at your usual distance. Inspect the center, edges, and corners without changing the image. Look for a broad tint, lighter or darker patches, vertical bands, or a repeated region that interrupts the otherwise uniform field. Use fullscreen when possible so surrounding page content does not distract you. Hide the field label to examine subtle differences and restore it to note the code used.
Toggle the location grid to describe where a feature appears. Each division is a location aid, not a measurement cell. Turn the grid off before judging severity because the lines create additional contrast. Keep the same display brightness and lighting while switching among near-black, dark gray, mid gray, light gray, and white. A feature visible on one field may become much less noticeable on another. The field choices are RGB values rather than percentages of measured panel luminance.
Inspect near-black OLED behavior and white tint
Near-black gray can reveal subtle banding or patches on an OLED that are less visible at middle levels. This does not make the darkest field a universal pass/fail standard. Panel processing, normal operating conditions, and your eye's adaptation affect what you see. Inspect the display after ordinary use and compare familiar dark content under the same conditions. Do not infer a hardware defect from one highly exposed phone photograph.
White and light gray make broad color tint differences easier to compare. Reflections from a colored wall, viewing angle, surface coatings, and the room's light can alter the appearance. Move your head slightly, return to center, and check whether the feature shifts. If it changes substantially with your position, use the viewing-angle test to investigate that contribution. On large monitors, moving farther back can reduce differences in angle between the center and corners.
Record persistent variation and useful next checks
A fixed feature that remains at the same position across repeated observations is useful information, but this tool cannot identify its physical cause. LCD backlight distribution, local dimming, OLED near-black behavior, image retention, and software processing can create different patterns. Leave optional image enhancements unchanged for a first observation, then compare one documented setting at a time. Keep brightness at your normal level rather than maximizing it simply to amplify a patch.
If you suspect temporary image retention, follow the manufacturer's normal care instructions and compare again later. Do not leave a static diagnostic field running for an extended session, apply pressure, or trigger undocumented repair routines. A web test does not repair the panel. It also cannot measure luminance uniformity, color temperature, or an acceptable manufacturing tolerance; instruments and a defined protocol are needed for numeric assessment.
Record the field code, screen location, brightness setting, room conditions, and whether the feature is visible in ordinary photographs, documents, or games. Consistent observations are more useful to support staff than a collection of photos with different exposures. Compare the contrast steps if shadow detail appears lost everywhere rather than in one region, and the backlight-bleed test if an LCD's black screen shows persistent bright edges. A small difference on an artificial field may have a different practical impact from a distracting patch during daily use.
Example: a stationary band versus a viewing-angle shift
Suppose a vertical darker band is visible on Mid gray. Use the grid briefly to describe its position, hide the grid, then compare Dark gray and White from the same centered seat. Record which fields reveal it rather than calling it burn-in from its shape alone. The selected RGB codes identify the images used; they are not measurements of the band's brightness or severity.
Now move your head slightly and return to center. A broad tint that changes with your position may include a viewing-angle contribution, whereas a band that remains at the same location is a persistent spatial observation. These checks do not establish the cause or a warranty threshold. Finish by checking whether the feature interrupts ordinary content, and avoid leaving a static field on an OLED for a prolonged inspection.
Frequently asked questions
Are the gray choices luminance percentages?
No. They are equal red, green, and blue digital code values. Display processing and transfer behavior determine emitted light, so RGB 128 is not a claim of fifty percent measured luminance.
What does the grid measure?
Nothing by itself. It divides the field into convenient screen locations so you can describe a patch. Hide it again before evaluating the uninterrupted gray or white field.
Is near-black OLED banding always a defect?
No single web pattern establishes that. Compare normal content, consistent settings, and repeated observations. The manufacturer can explain the applicable tolerances and assessment procedure for your model.
Can the page fix image retention?
No. It supplies inspection fields only. Follow the display maker's care instructions and avoid leaving static diagnostic patterns on screen for long periods or using undocumented repair methods.
Why does white look tinted at the edges?
Panel variation, off-axis viewing, reflections, and processing can contribute. Compare from a centered position with controlled room light, then use the viewing-angle patches to check position-dependent changes.