Before you begin, clean the display and sit at the distance you normally use it; dust, glare or an unusual viewing angle can affect what you notice. This check is useful when setting up a monitor or laptop screen, evaluating a used display, or comparing a change to its sharpness setting.
How to use Sharpness Test
- Select Start Test to open the patterns.
- Choose a setting from Pattern mode: Vertical alternating lines, Horizontal alternating lines, Checkerboard, Grid or Text. Each gives you a different kind of detail to inspect.
- Use Previous and Next to move between patterns, or press Left and Right. Compare the same pattern at your usual viewing distance.
- To cycle through patterns automatically, press Space. If reduced motion is enabled, progression stays manual; use Previous and Next instead.
- Select Fullscreen or press F for a larger view. Press Escape to exit fullscreen. In fullscreen on a phone, tap the left or right half to move between patterns; use the on-screen Exit button to leave fullscreen.
- Select Reset or press R to reset the test.
When to use it
- Checking a new monitor before the return window closes: Look for softness or distracting artifacts while you still have time to discuss concerns with the seller.
- Assessing a second-hand display: Compare lines, grids and text to get a quick sense of how different details look.
- Comparing monitor sharpness settings: Keep one pattern on screen while you adjust the display’s own sharpness setting, then judge the change at your normal viewing distance.
- After changing resolution or scaling: Check whether fine details and text look different from your usual setup.
- Investigating a soft-looking image: Compare several patterns, then check browser zoom and operating-system scaling if the appearance seems unexpected.
- Comparing a laptop screen with an external monitor: View the same patterns on each screen under your regular working conditions.
- Checking after reconnecting a display: Use the patterns as a quick visual check if clarity seems to have changed.
Tips for a useful sharpness check
Look at each pattern in turn rather than drawing a conclusion from a single image. Vertical and horizontal alternating lines emphasize fine detail in different directions; Checkerboard and Grid offer other structures to compare. If you are comparing display settings, change only the display’s setting you are investigating and return to the same pattern each time.
Text is a familiar reference, but its edges are deliberately browser-antialiased, so judge it as ordinary rendered text rather than a pixel-perfect target. Browser zoom, operating-system scaling and other display processing can also change how fine patterns appear. The pattern backing pixels are integer aligned, but that alone does not establish how many physical pixels the monitor is showing per sample.
Use a comfortable brightness and avoid reflections while inspecting the screen. Stop if bright patterns cause discomfort. If you want to check a wider range of display characteristics, try Monitor Test Patterns; for isolated pixel issues, use the more focused Dead Pixel Test.
Limits of Sharpness Test
This is a visual comparison, not a calibrated sharpness measurement or a way to confirm one physical pixel per sample. The result depends on the browser, zoom, operating-system scaling and the display’s own processing, so a pattern that looks soft or uneven is a reason to review the setup and compare settings, not proof of a fault.
If an issue remains visible across patterns and in everyday content, check the monitor’s settings and consult the seller or manufacturer. A browser test cannot establish the physical condition of a display or repair it.