Every pattern runs full screen, so the whole display is under test with no browser chrome in the way. Start with the first test or jump straight to one, then step through them with the arrow keys. Your files and inputs never leave your device.
In fullscreen:RightSpacenext,Leftprevious,1to24jump,Escexit.
Related tools
- Display InfoLive readout of your screen resolution, pixel density, refresh rate, color capabilities, and input features.
- Multitouch TesterVisualize simultaneous touch points, dead zones, and stylus pressure.
- Mouse Polling Rate and DPI TesterMeasure a mouse's actual polling rate in Hz and real DPI from a physical move, not the numbers printed on the box.
- Reaction Time TestMeasure visual reaction time across repeated trials, with false start detection and a comparison against typical human reaction.
- Key Rollover TesterCheck N-key rollover and ghosting visually by holding down keys and watching a live diagram.
- Media Key TesterVerify Media Session action handlers and hardware media keys, and see whether your headset or keyboard buttons actually reach the page.
What it does
A catalog of every classic monitor diagnostic pattern in one place: solid colors and a gray ladder for dead and stuck pixels, grayscale and color gradients for banding, a black field with a border for backlight bleed, checkerboard and a fine 1 pixel grid for scaling and sharpness, SMPTE-style color bars, near-black and near-white contrast steps, a gamma check with the matching formula, a viewing angle patch layout, panel inversion stripes, text clarity samples, and moving-block ghosting and motion blur tests.
How to use it
Pick a test from the list, or leave it on All tests to see the full catalog with a one-line purpose for each. Each test's instructions explain exactly what to look for and how to judge a pass or fail; turn on the SVG preview option to see the pattern itself alongside the description.
Why this one
Most monitor test sites are a single page of static images with no explanation of what a good result even looks like. This one pairs every pattern with plain instructions on what to look for, includes tests that are often missing elsewhere (panel inversion, viewing angle, a real gamma formula), and your files and inputs never leave your device.
FAQ
- How do I tell a dead pixel from a stuck pixel?
- Run the color cycle test and watch the same spot as the screen changes color. A dead pixel stays black through every color because it gets no power at all. A stuck pixel stays lit in one color, usually red, green, or blue, while the rest of the screen changes around it.
- Why does a gradient show visible bands instead of a smooth sweep?
- Most panels only drive 8 bits per color channel (256 shades), so a wide gradient like black to white can show visible steps between shades, especially when the panel or its driver skips dithering. A true 10-bit panel with proper dithering shows a much smoother sweep.
- Can a test pattern actually fix a dead or stuck pixel?
- The flashing color cycle test can sometimes coax a stuck subpixel back to normal by rapidly toggling it through every color, though it is not guaranteed and may take several minutes of running. A truly dead pixel receives no power at all, so no test pattern, however long it runs, can fix it.
Keyboard shortcuts: press ? anywhere on this page to see them.