Screen Issues is a free online resource for identifying, understanding, and troubleshooting display defects on monitors, laptops, phones, and tablets. The site is browser-only. There is no app to install and no file to download.
The interactive Screen Test runs full-screen solid colors in the browser: white, black, red, green, blue, and gray. A flat field makes small defects easier to see than a normal desktop wallpaper. You can look for dead pixels, stuck pixels, bright spots, black spots, backlight bleed, and color uniformity issues. The test is meant to take seconds.
A dead pixel stays dark because that pixel does not light. A stuck pixel stays on one color. Bright spots and black spots are localized marks that show against a solid field. Backlight bleed is uneven light around the edges of an LCD, most visible on a black screen in a dark room. Color uniformity problems show as a tint or a patch that does not match the rest of the panel. The solid-color modes exist so those patterns can be separated instead of guessed from a busy image.
Alongside the tool, Screen Issues publishes guides. The guides cover dead pixels, screen lines, flickering, pressure marks, and color or tint problems. They also cover device-specific cases for Mac computers, laptops, and mobile phones. The guides help a reader tell a panel defect from a cable, driver, or settings problem before paying for a repair.
The same material is available in English, German, Spanish, and Portuguese. Screen Issues was founded by Feng Zeng, Founder and Technical Director. The stated mission is to make screen diagnostics accessible to everyone. The price is free. The tool runs in the browser on the device you already have. No account is required to run the test. Screen Issues does not sell hardware.
Use the Screen Test when a display looks wrong and you need a controlled image. Open a solid color. Look at the panel from a normal viewing distance, then move closer if a mark is small. Compare the same spot on more than one color. A mark that appears on every color is more likely a panel defect. A mark that appears on only one color can be a stuck subpixel. A glow that only shows on black, near the edges, is the usual pattern for backlight bleed. Lines that run from edge to edge may be a panel or cable fault. The guides walk through how to tell those cases apart.
Start at the Screen Test page, run the colors, and open the matching guide if the pattern is still unclear. The site explains common display symptoms in plain language so a repair decision is based on what the screen actually shows. Content covers monitors, laptop panels, phone screens, and tablets. English is the primary language, with German, Spanish, and Portuguese versions of the same topics.
