A monitor test is a series of fullscreen patterns (solid colors, gradients, motion tests) that reveal dead pixels, backlight bleed, ghosting, color banding, and uniformity problems on any display. Run all six tests in this free suite in under three minutes, directly in your browser – no software to install. For buying recommendations after running these tests, see our gaming monitor buying guide. For more context, see all our hardware tests and tools.
Most dead pixel testers only cycle through solid colors. This suite includes motion tests for ghosting and blur, gradient displays for color banding, and a backlight bleed check designed for dark room evaluation. Run these tests within the first 30 days of buying a new monitor – most manufacturers accept returns for dead pixel defects within this window.
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How to Test Your Monitor (Step-by-Step)
Follow these seven steps in order. Total time is about three minutes. Do the backlight bleed step after dark for accurate results. Pair this with our dedicated dead pixel test if you want a pixel magnifier and defect locator.
- Enter fullscreen mode. Click any test card in the suite below to launch that pattern in fullscreen. Fullscreen is required so the browser UI does not cover edges and corners where defects hide.
- Cycle solid color screens for dead and stuck pixels. Launch the Dead Pixel Test and click to advance through red, green, blue, white, black, and 50% gray. Scan the screen in sections – dead pixels look like tiny dots that do not match the background color. White shows dead (black) pixels best; colored backgrounds reveal stuck sub-pixels.
- Check backlight bleed on a black screen. Turn off room lights, set monitor brightness to 30-50%, then run the Backlight Bleed Test. Look for bright patches or glow at the edges and corners. Distinguish bleed (stays in place when you move your head) from IPS glow (shifts with viewing angle).
- Evaluate a gradient for color banding. Run the Color Gradient Test. Smooth gray, red, green, and blue gradients should transition cleanly from dark to light. Visible stair-step bands mean limited color depth (6-bit panel) or bad gamma calibration.
- View color blocks to check color accuracy. Run the Viewing Angle Test and switch to the Color Block pattern. Compare red, green, blue, yellow, magenta, and cyan blocks for correct hue – magenta should not lean pink, cyan should not lean green. Tilt your head to check how color shifts off-axis.
- Confirm contrast with mid-gray uniformity. Run the Uniformity Test. A mid-gray fullscreen should look even across the panel. Dark bands on the sides or a warm tint in one corner indicate poor backlight uniformity, common on budget IPS monitors.
- Test response time with the motion pattern. Run the Motion Blur Test at slow, medium, and fast speeds. If you see a shadow trail behind the moving box at slow speed, your panel has noticeable ghosting. Bright coronas ahead of the box mean overdrive is set too aggressively – lower the response time setting in your monitor OSD by one level.
Document any defects with close-up photos before contacting the manufacturer for a return. Most brands accept dead pixel RMAs within 30 days of purchase.
Monitor Test Suite
Click any test card below to launch it in fullscreen. Once in fullscreen, click anywhere to cycle to the next pattern or press Escape to exit.
Cycles through red, green, blue, white, black, and gray fullscreen patterns. Dead or stuck pixels show as tiny dots that do not match the background color.
Pure black fullscreen. Turn off room lights and look for bright spots or light leaking from edges and corners – that is backlight bleed. Adjustable brightness levels.
Smooth gradients from dark to light in gray, red, green, and blue. Visible banding (stair-stepping) means your panel has limited color depth or poor gamma calibration.
Moving objects at different speeds. If you see trailing shadows behind the moving object, your monitor has noticeable ghosting. Faster panels produce cleaner edges.
Shows a test pattern designed to reveal color shift and contrast loss at off-center viewing angles. Move your head side to side – IPS panels hold color, VA panels wash out.
Mid-gray and mid-color fullscreen patterns. Uneven brightness or color tinting across the panel indicates poor backlight uniformity – common on budget IPS monitors.
Dead Pixel Guide
Dead pixels are individual sub-pixels on your display that fail to light up or get stuck in one color. They are manufacturing defects in the LCD/OLED panel itself. There are three types:
Types of Pixel Defects
| Defect Type | Appearance | Cause | Fixable? |
|---|---|---|---|
| Dead pixel | Always black – never lights up | Transistor failure on the panel | No – permanent hardware failure |
| Stuck pixel | Stuck on one color (red, green, or blue dot) | Sub-pixel transistor stuck in “on” state | Sometimes – pixel cycling or gentle pressure can fix |
| Hot pixel | Always white – all sub-pixels stuck on | All three sub-pixel transistors stuck open | Rarely – same techniques as stuck pixels |
Run the dead pixel test on each color. A dead pixel is easiest to spot on white. A stuck red sub-pixel is easiest to spot on a green or blue background. Scan each solid color screen carefully, section by section – single-pixel defects are small and easy to miss if you scan too quickly.
Need more than basic color cycling? Our standalone Dead Pixel Test includes a pixel magnifier, coordinate locator for documenting defect positions, a stuck pixel fixer with timer, an interactive defect identifier, and a warranty return calculator covering 13 brands.
Return Policies for Dead Pixels
Manufacturer policies vary widely. Some brands like Dell replace any monitor with even 1 dead pixel. Others like ASUS and Samsung require 3-5 dead pixels or a bright pixel in the center region before approving a warranty claim. Always document dead pixels with close-up photos showing the defect location and color before contacting support.
Backlight Bleed Explained
Backlight bleed is light leaking from the edges or corners of an LCD panel. It shows up as brighter areas on an otherwise black screen. Every LCD panel has some backlight bleed because the backlight (LEDs behind or beside the panel) cannot be perfectly blocked. OLED monitors do not have backlight bleed because each pixel produces its own light.
How to Test
- Wait until nighttime or close blinds – the room needs to be dark
- Run the Backlight Bleed Test above (pure black fullscreen)
- Set your monitor brightness to 30-50% (max brightness exaggerates bleed)
- Look at the edges and corners for bright patches or glow
- Some glow directly in front of your sitting position is IPS glow (panel trait, not a defect)
Bleed vs IPS Glow
IPS glow and backlight bleed look similar but have different causes. IPS glow is a silver or warm glow that appears in corners when viewed from your normal seating position – it shifts or disappears when you change your viewing angle. Backlight bleed stays in the same spot regardless of angle because it is physical light escaping around the panel frame. IPS glow is inherent to IPS panel technology and is not a defect. Backlight bleed can vary unit-to-unit and severe cases are grounds for a return.
Understanding Motion Blur and Ghosting
Motion blur on monitors happens because pixels take time to transition from one color to another. During this transition, the pixel displays an intermediate color – which your eyes perceive as a smeared trail behind moving objects. This is called ghosting.
What Affects It
- Panel response time – measured in milliseconds (ms). Lower is better. Marketing claims like “1ms” often measure gray-to-gray in ideal conditions. Real-world transitions (especially dark-to-light) can take 5-15ms on some panels.
- Refresh rate – higher refresh rates (144Hz, 240Hz, 360Hz) reduce the time each frame is displayed, which reduces perceived blur from sample-and-hold.
- Overdrive settings – monitor overdrive (sometimes called “response time” in the OSD) pushes pixels to transition faster. Too much overdrive causes inverse ghosting – bright coronas ahead of moving objects. Find the setting that eliminates trailing without adding coronas.
Panel Types Ranked by Motion Clarity
| Panel | Typical GtG | Motion Clarity | Best For |
|---|---|---|---|
| OLED | 0.03-0.1ms | Near-perfect | Competitive FPS, fast-paced games |
| TN | 1-2ms | Good | Budget competitive gaming |
| Fast IPS | 1-4ms | Good | All-around gaming + content |
| VA | 4-10ms | Moderate | Single-player, movies, contrast lovers |
Run the motion test at all three speeds. If you see a visible shadow trail at slow speed, your panel has significant ghosting. Most modern IPS gaming panels show minimal ghosting at slow and medium speeds, with some visible trailing only at the fast setting. VA panels typically show ghosting at all speeds due to slower dark-transition response times.
Time for an Upgrade?
If your monitor shows dead pixels, heavy backlight bleed, or noticeable ghosting, these guides cover every price range and panel type. For specific problems, see our monitor ghosting fix guide or our monitor flickering troubleshooter.
- Best 1440p Gaming Monitors – the sweet spot for resolution and refresh rate. Most popular choice for FPS and competitive gaming in 2026.
- Best Monitors for FPS Games – prioritizes refresh rate and response time over everything else. 240Hz+ panels with minimal ghosting.
- Best 4K Gaming Monitors – for single-player games and productivity where resolution matters more than raw speed.
If backlight bleed is your biggest frustration, consider an OLED monitor. OLED produces true black (the pixel is off) so backlight bleed is physically impossible. The tradeoff is higher cost and burn-in risk with static content.
Frequently Asked Questions
How do I check for dead pixels on my monitor?
Launch the Dead Pixel Test above in fullscreen and cycle through red, green, blue, white, black, and 50% gray screens. A dead pixel appears as a tiny dot that stays a different color from the background. Scan each color in sections, moving your eyes systematically across the entire screen. Dead (always black) pixels are easiest to spot on a white background, while stuck sub-pixels stand out against green or blue.
Can dead pixels be fixed?
Dead pixels (always black) cannot be fixed because the transistor driving that pixel has permanently failed. Stuck pixels (always one color) are fixable about half the time: run pixel-cycling software that rapidly flashes red, green, and blue for 30-60 minutes, or gently press a microfiber cloth on the pixel while the screen cycles colors. Pixels stuck for longer than a week rarely recover.
How much backlight bleed is acceptable?
Acceptable bleed means no bright patches are visible during normal use at 30-50% brightness with room lights on. Every LCD monitor has some bleed since the LED backlight cannot be perfectly blocked around the panel frame. Request a replacement if bright spots stay visible during dark movie scenes or dark game areas at normal brightness settings. Phone camera photos exaggerate bleed due to long exposure times, so judge with your eyes.
What is the difference between ghosting and inverse ghosting?
Ghosting is a dark trail behind moving objects caused by slow pixel transitions. Inverse ghosting is a bright or light-colored halo ahead of moving objects caused by monitor overdrive being set too aggressively. Inverse ghosting is the worse artifact since bright coronas are more distracting than dark trails. Fix it by lowering the overdrive or response time setting in your monitor OSD by one level until the coronas disappear.
Does refresh rate affect dead pixel tests?
No. Dead pixel tests display static solid colors, so refresh rate has zero effect on results. Dead pixels are hardware defects in the panel, not rendering issues, and show up at any refresh rate. Refresh rate only matters for the motion blur test, where higher refresh rates (144Hz, 240Hz, 360Hz) reduce perceived ghosting by shortening how long each frame is displayed.
Do these tests work on laptops and tablets?
Yes. The suite works on any device with a modern browser that supports fullscreen mode, including laptops, tablets, and phones. On tablets, tap a test card to enter fullscreen and tap again to cycle patterns. Dead pixel, backlight bleed, and gradient tests apply equally to laptop displays and tablets because they use the same LCD and OLED panel technology as desktop monitors.
Sources and References
- ISO 13406-2 standard on pixel defect classification – defines Class I through IV tolerances for LCD displays used by most manufacturers in return policies
- TFTCentral response time measurement methodology – explains gray-to-gray transition measurement and why marketing GtG claims differ from real-world pixel persistence
- VESA DisplayHDR specification on backlight zone requirements – documents local dimming zone counts and edge-lit vs direct-lit backlight architectures
