Thin upright lines on mid gray, black above, white below
Thin upright lines on mid gray, black above, white below
Preview · enlarged so the lines show
Black lines one pixel wide and seven pixels apart cross a level 128 field, and white lines fill the lower third. At neutral sharpness the gray runs flat right up to each line. Look close for a rim beside them.
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Thin upright lines on mid gray, black above, white belowBlack lines one pixel wide and seven pixels apart cross a level 128 field, and white lines fill the lower third. At neutral sharpness the gray runs flat right up to each line. Look close for a rim beside them.
Thin level lines on mid gray, black above, white belowThe same lines lying flat. Sharpening can act across the screen only, down it only, or both by different amounts, so a control that looks neutral on the upright lines can still leave a rim here.
Wide black lines on mid gray, 2, 4 and 8 pixelsBlocks of black lines 2, 4 and 8 pixels wide with gray gaps of the same width, upright and level. In the widest block a rim is broad enough to see from your chair: each gray gap looks lighter at its edges.
Show all 17 patterns and checks (14 more)
Sharpness patterns, continued
Thin lines at full contrast, black on white, white on blackDark strokes on a white page above, light strokes on a black one below. White cannot get whiter nor black blacker, so a rim that shows on gray can pass unseen here. Use it to see how thin strokes look once the control is set.
Small gray steps beside mid graySix bars, from 24 levels darker than the level 128 field to 24 lighter, each numbered and set between bars of the field. Each should be one even shade to its edge. A light line on one side of an edge and a dark one on the other is sharpening.
Small text, dark on light and light on darkThe browser's own text at six sizes from 9 to 22 CSS pixels, on white and on black. Sharpening gives small letters more contrast and, past neutral, a pale rim. Judge the control on the lines, then confirm it here.
What you see and which way to turn 6
A pale rim beside the black linesSharpness is above neutral: the gray next to each black line has been pushed lighter than the gray around it. Lower the control one step and look again. The rim should thin out and then disappear.
A dark rim beside the white linesThe same fault seen from the other side: beside a white line the gray is pushed darker than the gray around it. Either rim means the control is above neutral, so keep stepping down until both are gone.
Lines that turn gray or wider than a pixelEither the control is below neutral, where it softens the boundary between light and dark, or the picture is being resized before it reaches the panel. Raise Sharpness one step. If nothing sharpens, check zoom and resolution.
A rim beside upright lines onlyThe monitor sharpens in one direction. That is a known form of edge enhancement, not a fault in the pattern or in your eyes. Set the control on whichever lines show the rim; the other direction needs nothing.
A second, fainter echo outside the rimRinging, the mark of a picture sharpened twice. The first filter makes new edges beside the real ones and the second enhances those too. Look for another sharpening setting, in the graphics driver or in a game, and turn that one off.
Red and blue edges on the text onlyNot the Sharpness control. Operating systems sharpen small text by lighting the red, green and blue parts of a pixel separately, which leaves faint colored edges on letters and none on these lines. Leave the monitor alone.
What to change, in order 5
First make one line land on one pixelReset page zoom to 100 percent: zoom changes how many screen pixels a CSS pixel covers, and a line spread over two pixels looks soft at any setting. The line under the picture says when a one-pixel line may not fit.
Then send the panel its own resolutionA flat panel has one fixed grid of pixels. Sent any other resolution it has to rescale the picture, which costs sharpness that no control gives back. Choose the panel's native resolution in the operating system's display settings.
Then Sharpness, one step at a timeOpen the monitor's menu and move Sharpness a step. Stop where the gray is flat beside every line and each line is still one clean pixel. That step is neutral: the control neither adds an outline nor softens.
Why this page gives no numberThe answer is a step on your monitor's own scale, and a page cannot know where that scale puts neutral. The pattern finds it on any scale: the step where the rim goes and the lines stay crisp is your number.
A step above neutral is a choiceNeutral is the faithful setting, not a rule. A picture seen from farther away, or with weaker eyesight, can take a little more edge enhancement than one seen up close. If small text reads better one step up, keep it.
How this list was compiled: The patterns are this site's own drawings. Computed: the thin lines are one pixel wide and seven pixels apart on a level 128 field, and the small gray steps are bars at levels 104, 116, 124, 132, 140, 152, from 24 levels darker than the field to 24 lighter, with a bar of the field's own level between each two. That edge enhancement raises the contrast around an edge and leaves a bright and a dark highlight on either side of it (overshoot and undershoot), that a television's sharpness control is an example of it, that it can be applied in the horizontal or the vertical direction only or in both by different amounts, that it improves only perceived sharpness and loses some detail, that sharpening an already sharpened picture leads to ringing because the first filter creates new edges beside the real ones, and that the amount that looks right depends on the viewing distance, the display size and the viewer's eyesight, is from https://en.wikipedia.org/wiki/Edge_enhancement. That a picture with higher acutance looks sharper although its real resolution is unchanged, and that overdone it shows as two halos beside a line, one dark and one bright, is from https://en.wikipedia.org/wiki/Acutance. That many LCD monitors have a sharpness control that can strengthen or soften the boundaries between light and dark areas, that ideally it does neither, and that fringes show around black and white bars when it is far off, is from http://www.lagom.nl/lcd-test/sharpness.php, whose test image is not used here. That subpixel rendering is used mainly for text on standard-density displays and has inherent color anomalies is from https://en.wikipedia.org/wiki/Subpixel_rendering. That a flat panel has a single fixed resolution and must scale any other, with a loss of sharpness, is from https://en.wikipedia.org/wiki/Native_resolution. That page zoom changes the ratio of screen pixels to CSS pixels is from https://developer.mozilla.org/en-US/docs/Web/API/Window/devicePixelRatio. All read 2026-10-06. The page measures nothing and names no number for any maker's menu: the neutral step is found by eye. Licence: own work
How it works
What sharpness should my monitor be? The step where the control adds nothing and takes nothing away. Thin lines on mid gray find it: above it a pale rim appears beside each line, and below it the lines turn soft.
Read the full guide
Find the neutral step
1. Reset page zoom to 100 percent and press Go full screen.
2. Look close at the black lines. A pale rim on the gray beside them means Sharpness is too high.
3. Lower Sharpness in the monitor's menu one step at a time until the gray is flat right up to each line.
4. If the lines turn gray or soft, you have gone too far: go back one step.
Questions and answers
What does the sharpness setting do on a monitor?
It applies edge enhancement: contrast is raised right at the edges in the picture. That looks crisper from a distance but adds no detail, and some is lost. Set below neutral, the same control softens edges instead.
Why does my monitor look blurry at every sharpness setting?
Then the control is not the cause. Check whether the picture is being resized before it reaches the panel: reset page zoom to 100 percent, choose the panel's native resolution, then read your real pixel count on the 4K monitor test.
Why does text on my monitor have a white outline?
Sharpness is set above neutral. Edge enhancement leaves a bright highlight on one side of every edge and a dark one on the other, plainest on gray or colored backgrounds, and small text is nearly all edges. Lower the control until the outline is gone.