LCD Screen Test
Check your LCD screen for dead pixels, backlight bleed, uneven areas, black-level issues, motion problems, and other visible display defects.
Workflow
LCD Screen Check
Work through these checks in order on the LCD display you want to test. All tests run in your browser.
0 / 8 checked
Method
How to test your LCD screen
Set normal display settings. Use your normal picture or display mode. Avoid unusual color filters or extreme settings that significantly change the image.
Set the display to your intended resolution. Browser testing cannot independently verify the panel's physical native resolution.
Use a dark room for black-screen checks. Low ambient light makes backlight bleed, glow, and dark-screen unevenness easier to see.
Run the tests fullscreen. Use fullscreen where supported and inspect the LCD display itself.
Check from normal viewing distance. Inspect the screen from your usual position, then move closer when checking pixels or small defects.
Check the entire panel. Inspect the center, edges, corners, and large uniform areas.
Check viewing angles when useful. For LCD panels, compare the appearance of gray and dark areas from your normal viewing position and modest changes in viewing angle.
Record anything unusual. Take photos or notes if testing a new or used LCD before the return period ends.
What to look for
- Dark, bright, or stuck pixels
- Visible light around edges or corners
- Uneven gray or white areas
- Gray blacks or lost near-black detail
- Visible gradient banding
- Motion trails or smearing
- Inverse ghosting or halos
- Unexpected observed refresh-rate results
New vs used LCD
New LCD
Focus on dead pixels, backlight bleed, gray uniformity, resolution, black-level behavior, and obvious display defects.
Used LCD
Also check for uneven areas, visible backlight issues, dark or bright patches, image artifacts, motion problems, and signs of previous display wear.
LCD panel types
IPS
IPS displays can show angle-dependent corner glow and changes in appearance when viewed from different angles. Use the Backlight Bleed and Greyscale & Uniformity tests to inspect these visually.
VA
VA displays can show dark-scene uniformity differences and motion smearing. Use the Black Level, Greyscale & Uniformity, and Ghosting tests to inspect these visually.
TN
TN displays can show stronger changes in appearance with viewing angle. Use gray and solid-color patterns to inspect the display from your normal viewing position.
Explained
What to check on an LCD screen
Light from the LCD backlight that is visible where the screen should appear dark, especially around edges or corners.
Angle-dependent glow that can become more or less visible as your viewing position changes. A browser test can help you observe it but cannot objectively classify its severity.
Whether large gray or white areas appear even across the panel.
How black and near-black shades appear and whether dark details remain distinguishable.
Smooth gradients appearing as visible steps or bands.
Visible trails or smearing behind moving objects.
Visible darker, brighter, or cloudy areas across a large uniform field. Browser testing can help reveal these visually but cannot determine their manufacturing cause.
What browser testing can and cannot check
Browser tests can help you visually inspect
- Dead pixels
- Backlight bleed and visible glow
- Gray and screen uniformity
- Black and near-black detail
- Color banding
- Motion trails and inverse ghosting
- Observed browser frame cadence
Browser tests cannot reliably measure
- Actual contrast ratio
- Peak brightness or nits
- Exact response time in milliseconds
- Actual color accuracy or Delta-E
- Actual color-gamut coverage
- Physical panel native resolution in every environment
- LCD backlight lifespan
- Exact panel type from browser APIs
- Hardware VRR or adaptive-sync behavior
- PWM frequency
FAQ
LCD Screen Test FAQ
01How do I test an LCD screen?
Open this page on the LCD display and work through the eight checks in order, using fullscreen where possible.
02How do I check an LCD screen for dead pixels?
Cycle through solid black, white, red, green, and blue backgrounds and look for pixels that never change.
03How do I test an LCD screen for backlight bleed?
Display a black screen in a dark room and inspect the edges and corners for visible light leakage, glow, or uneven areas.
04How do I tell IPS glow from backlight bleed?
Change your viewing position. Glow shifts with viewing angle, while fixed light leakage stays in the same place.
05How do I test an LCD screen for uniformity?
Use full gray fields and compare the center, edges, and corners for uneven brightness or tint.
06How do I test an LCD screen for black levels?
Use pure-black and near-black patterns in a dark room and check whether very dark shades stay distinguishable.
07How do I test an LCD screen for ghosting?
Watch the moving ghosting pattern fullscreen and look for visible trails, smearing, or inverse ghosting.
08How do I test an IPS display?
Run the backlight bleed and greyscale tests, and compare gray and dark areas from your normal position and modest angle changes.
09How do I test a VA display?
Run the black level, greyscale, and ghosting tests, watching dark-scene uniformity and motion smearing.
10How do I test a TN display?
Use gray and solid-color patterns viewed from your normal position, since appearance shifts with viewing angle.
11Can I test an LCD screen without downloading anything?
Yes. Every check on this page runs in a browser with nothing to install.