Run a Full Monitor Test in Your Browser
Monitor test puts your display through 12 categories of full-screen patterns so you can spot dead pixels, color and uniformity flaws, banding, and ghosting in minutes. Open it in any browser, go fullscreen, and check a new screen for defects or fine-tune an old one.
Each category bundles the right patterns for the job: solid colors for a dead pixel test, gray fields for backlight bleed, smooth gradients for banding, and a moving box for response time. An Info panel on every test tells you exactly what a good and a bad result looks like, so you never have to guess.
How to Test Your Monitor
Go fullscreen
Press F or click the fullscreen button so browser bars and the taskbar don't cover the screen edges. Fullscreen is recommended for accurate uniformity and border checks.
Pick a test category
Choose one of the 12 cards on the menu, or hit Run All Tests to start from Defective Pixels. Begin with Defective Pixels for a quick check or Test Patterns for an overview.
Click or scroll to navigate
Click anywhere (or press →) to move to the next test in a category. Scroll the mouse wheel, or use the bottom pills, to switch between categories.
Read the result
Open the Info panel (press I) for a "what to look for" guide with the good and bad result for each pattern. For interactive tests, drag the on-screen sliders to push your display harder.
12 Test Categories
Defective Pixels
Fill the screen with 9 solid colors to find dead, stuck, or hot pixels. An Auto Cycle mode steps through the colors hands-free.
Test Patterns
Broadcast-grade references: a Master Test Pattern, SMPTE Bars, Black Level (Pluge), Primary Colors, and grayscale ramps and steps.
Uniformity
Even gray fields from 5% to 75% reveal backlight bleed, IPS glow, clouding, and vignetting across the whole panel.
Color Distances
An interactive test with RGB sliders and a live ΔE readout, plus a hue wheel and red, green, and blue shade ramps to test how fine a color difference you can see.
Contrast
A black-and-white split plus near-black and near-white shade ramps check that highlights aren't blown out and shadow detail isn't crushed.
Gamma
Compare a blended checkerboard against a solid gray block to verify your gamma is correctly set to 2.2 for accurate mid-tones.
Gradients
Grayscale and red, green, and blue gradients, plus near-black and near-white ramps, expose color banding from low-bit panels or limited RGB output.
Sharpness
Vertical and horizontal lines, a grid, and an interactive text test (adjust font size, text color, and background) confirm crisp pixels and native resolution.
Viewing Angle
Gray, red, green, and blue fields show how much color and contrast shift when you look at the screen off-center — useful for VA and TN panels.
Geometry
A circle, grid, and border pattern check for shape distortion, aspect-ratio errors, and overscan that cuts off the screen edges.
Response Time
A moving box reveals ghosting and motion blur. Adjust speed (up to 100), object count (up to 20), and the background and object colors.
Burn-in Fix
High-speed white noise that rapidly switches every pixel. Run it for 10–20 minutes to try to unstick pixels or clear image retention.
Controls and Shortcuts
Click or arrows
Click the screen or press → / ← to move to the next or previous test within a category.
Scroll to switch categories
In fullscreen, roll the mouse wheel up or down — or use ↑ / ↓ — to jump between the 12 categories.
Auto Cycle
In Defective Pixels, press Space to auto-cycle the solid colors hands-free, so you can inspect the panel without clicking.
Fullscreen and Info
Press F to toggle fullscreen, I for the Info panel, and H or Esc to return to the home menu.
Frequently Asked Questions
How do I test my monitor for dead pixels?
Open the Defective Pixels category and step through the 9 solid colors (use Space for Auto Cycle). On each full-color screen, look closely for any dot that doesn't match the background — that pixel is dead, stuck, or hot. Going fullscreen and viewing from a normal distance makes faults easier to spot.
What is the difference between a dead pixel and a stuck pixel?
A dead pixel never lights up, so it stays black on every color. A stuck pixel is frozen on one color (often red, green, or blue) and shows on most backgrounds. A hot pixel is always fully lit and appears white. The solid-color screens make all three easy to identify.
How do I fix a stuck pixel?
Run the Burn-in Fix category, which fills the screen with high-speed white noise. Leaving it on the stuck pixel for 10–20 minutes can sometimes "massage" it back to life by rapidly cycling its sub-pixels. True dead pixels are usually permanent and can't be fixed in software.
Can this fix monitor burn-in?
The Burn-in Fix noise can help clear temporary image retention on LCD and OLED screens by exercising every pixel. Permanent OLED burn-in — where the panel is physically worn — generally cannot be reversed, but running the pattern for 10–20 minutes is a safe first thing to try.
Does fullscreen matter for the test?
Yes. Browser bars and the taskbar can hide the screen edges, which is exactly where uniformity, border, and overscan problems show up. Fullscreen also lets some patterns cover the whole panel, giving a more accurate read of real display quality.
What do the solid color screens check for?
Each solid color forces every pixel to display the same value, so any pixel that differs stands out instantly. Bright colors expose dead pixels, black exposes stuck and hot pixels, and the gray fields in the Uniformity category reveal backlight bleed, clouding, and IPS glow.
Why do I see banding in the gradients?
Visible steps in a smooth gradient usually point to a 6-bit panel (which fakes colors with dithering), a graphics card set to a limited RGB range instead of full, or 8-bit output on a 10-bit display. Switching to full RGB range and your panel's native bit depth often clears it up.
How do I know if my gamma is correct?
In the Gamma test, view the blended checkerboard pattern next to the solid gray block from a normal distance. If both look equally bright, your gamma is correctly set to 2.2. If the checkerboard looks lighter, gamma is too high; if it looks darker, it's too low.
Is my data sent anywhere?
No. Every pattern is drawn in your browser using your device's own graphics. No test data, screenshots, or personal information is collected or sent to any server — the tool runs entirely on your machine.
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