YAQUIZO
Create free

Image Sharpener

Real unsharp mask controls — amount, radius and threshold — with a 100% viewer, because sharpening cannot be judged any other way. Free, in your browser, never uploaded.

Drop an image here

or choose one from your device. JPG, PNG and WebP.

Your image never leaves this device. Everything happens in your browser.

Worth knowing before you start: sharpening cannot fix a blurred photo. It works by increasing contrast either side of an edge, which the eye reads as crispness — but it does not recover detail, because detail the lens never resolved is not in the file to recover. A slightly soft image can be improved markedly. A genuinely out-of-focus one cannot, and pushing the sliders harder produces halos rather than clarity.

The second thing that trips people up is the preview. Sharpening acts on fine detail, so showing a 4000-pixel photo at 600 pixels wide discards the very thing you are trying to judge — the effect looks like it is doing nothing at all. That is why this opens at 100% and treats zoom as a main control rather than a convenience. Drag to move around, and hold Compare to flip back to the original.

The threshold control is the one worth learning. Amount and radius decide how strong the effect is; threshold decides where it applies at all. Set it above the level of the grain in a sky or the texture in skin and those areas are left alone entirely, while real edges keep their sharpening. It is the difference between a photo that looks crisp and one that looks processed.

How to sharpen an image

  1. 1. Open your image

    Drag it onto the drop zone or choose it from your device. The viewer opens at 100%, because sharpening cannot be judged at any smaller size.

  2. 2. Start with a preset

    Subtle for portraits, Standard for most web photos, Strong for soft scans, Extreme for text and line art. Each sets amount, radius and threshold together.

  3. 3. Refine and compare

    Adjust amount, radius and threshold, drag the image to inspect a detailed area, and hold Compare to check it against the original.

  4. 4. Download it

    The full-resolution image is sharpened once with your settings and downloads immediately. Keep quality high so the new detail is not compressed away.

What the three controls do

Frequently asked questions

How do I sharpen an image for free? +

Drop the image above, pick a preset, adjust it if you want, and press Sharpen and download. There is no account, no watermark, and the file is never uploaded — everything runs in your browser.

Can this fix a blurry photo? +

No, and it is worth saying so before you spend time on the sliders. Sharpening increases contrast either side of an edge, which makes an image read as crisper. It does not recover detail, because detail the lens or the sensor never resolved simply is not in the file. A slightly soft photo can be improved a great deal. A genuinely out-of-focus or motion-blurred one cannot be rescued by any sharpening tool, and pushing harder produces halos rather than clarity.

Why does the sharpening look like it is doing nothing? +

Almost always because you are looking at a downscaled view. Sharpening works on fine detail, and displaying a 4000-pixel photo at 600 pixels wide throws that detail away before you ever see it. That is why this viewer opens at 100% rather than fitting the image to the screen — switch to Fit and the same effect will appear to vanish.

What do amount, radius and threshold do? +

Amount is how much extra contrast is added at each edge — the overall strength. Radius is how far either side of the edge that contrast spreads; small values look crisp, large ones produce visible bright and dark halos. Threshold is how different two areas must be before the effect applies at all, which is what stops grain in a sky or texture in skin being amplified into speckle. Threshold is the control most tools leave out and the one that most separates a natural result from an over-processed one.

What is an unsharp mask? +

The standard sharpening method, and confusingly named. The tool makes a blurred copy of your image, subtracts it from the original to find where the edges are, and then adds that difference back with extra weight. The "unsharp" refers to the blurred copy used as a reference, not to the result.

My sharpened image looks speckled or noisy — what went wrong? +

The threshold is too low for that image, so grain and compression noise in flat areas is being treated as edge detail and amplified. Raise the threshold until the flat areas settle down; the real edges will keep their sharpening because their differences are much larger than the noise.

What are the bright outlines around objects? +

Halos, caused by too much amount, too large a radius, or both. They are the classic sign of over-sharpening. Reduce the radius first — it usually does more damage than amount — and check the result at 100% rather than zoomed out, where halos hide.

Does sharpening make the file bigger? +

Usually yes, and sometimes noticeably. Sharpening adds fine high-contrast detail, which is exactly what lossy compression finds expensive to store. It also means a low quality setting will throw much of your new detail straight back away, so keep quality high when saving as JPG or WebP, or use PNG.

Is my image uploaded anywhere? +

No. The image is decoded, sharpened and re-encoded entirely inside your browser, and nothing is transmitted. Once the page has loaded it works offline.

Will there be a watermark? +

No. The output is your image with the sharpening applied and nothing else added. There is no watermark, no sign-up, and no paid tier.

Other free tools