Free screen and monitor tests
Test your screen for defects and settings problems
20 browser-based tests for monitors, laptops, phones, and TVs. Each test makes a problem easy to see, explains what causes it, and shows how to fix it or document it for a return.
No install or account. Results you save stay in this browser; you choose what to export.
Common display problems
What are you seeing?
Pick the problem you see. Each test page explains the likely causes and how to fix them.
A dot stays in one place
Cycle solid colors to tell a dead, stuck, or hot pixel from dust, and note exactly where it is.
Run the dead pixel testA corner glows in dark scenes
Find out whether it is backlight bleed or IPS glow by moving your head in front of a black screen.
Run the backlight bleed testLetters are soft or have colored edges
Check scaling, ClearType, and subpixel layout on fixed sample text.
Run the text clarity testMoving objects leave a trail
Compare overdrive levels on moving patterns to find the setting with the least ghosting and overshoot.
Run the response time testAn old image stays visible
Check solid colors for burn-in, and learn how to tell temporary retention from permanent wear.
Run the burn-in testSmooth shades break into bands
Find out whether banding comes from the file, the graphics settings, or the panel.
Run the banding testAll 20 screen tests
Grouped by what they check. Not sure where to start? The monitor testing guide gives a full order.
HDR and color behavior
HDR Capability Check
Check HDR support and the settings that turn HDR on.
Gradient Banding Test
Look for color banding and find out where it comes from.
Gamma Test
Match stripes to solid patches to see which gamma your display is closest to.
Black and White Detail Check
Check for crushed blacks and clipped whites.
Color Temperature Test
Compare white point presets and night modes on one white reference.
Pixels, uniformity, and panel defects
Dead Pixel Test
Find dead, stuck, and hot pixels with solid colors.
Touch Screen Test
Find touchscreen dead zones and count simultaneous touches.
Uniformity Test
Check for uneven brightness, clouding, and color tint.
Burn-in Test
Check OLED and plasma screens for burn-in and image retention.
Backlight Bleed Test
Spot backlight bleed and IPS glow on a black screen.
Viewing Angle Test
See how color and contrast shift as you move off-center.
Motion, frame timing, and interaction
Response Time Test
Spot ghosting, overshoot, and motion blur on moving patterns.
Refresh Rate Test
See the frame rate your browser renders and check frame pacing.
Frame Skipping Test
Photograph a numbered frame sequence to catch dropped frames.
Browser Reaction Time Check
Measure your reaction time and see where input delay comes from.
Flicker Test
Use your phone camera to spot PWM flicker.
Text and viewing comfort
Screen information and multi-display setup
Worked explanations
Three differences worth checking
More pixels, same workspace. 3840 × 2160 at 150% scaling works out to the same 2560 × 1440 logical area as QHD at 100%. Density and room for windows answer different questions. Compare all four setups and download the calculations.
Same average fps, different gaps. Twelve new frames in 200 ms averages 60 fps whether intervals are even or include two 50 ms waits. See the timing diagram before treating a delivery hitch as a pixel-response problem.
Same words, different source detail. Enlarging a 120 × 40 image to 360 × 120 CSS pixels gives existing samples more space; it does not add the missing letter detail. Compare the raster with live text to see why changing the monitor may not address a soft source.
These are worked calculations. To check your own screen, follow the monitor testing guide.
Practical guides
Fix problems and buy with confidence
How to Test Your Monitor
A step-by-step order for checking a new or used display at home.
Dead Pixel Warranty Guide
Prove a pixel fault, find the policy that applies, and write a clear support request.
Gaming Monitor Settings
Fix stutter, motion trails, and dim or washed-out HDR, one setting at a time.
Troubleshoot Blurry Text
Find out whether blur comes from the file, the app, or a display setting, and fix it.
Understand Monitor Specifications
Work through resolution, scaling, refresh rate, and HDR badges with real numbers.
Monitor Panel Types Explained
IPS, VA, TN, OLED, and Mini-LED compared: contrast, viewing angles, motion, and typical artifacts.
HDMI vs DisplayPort vs USB-C
Which connection and cable your monitor needs, and how to fix 60 Hz limits and dropouts.
Monitor Buying Worksheet
Check a monitor against its manual before you buy, with a downloadable worksheet.