Summary

This free AI image sharpener sharpens soft photos directly in your browser, with no upload and no signup. It uses a classic unsharp mask: it finds edges by blurring a copy of your image, then boosts them with three sliders, amount, radius and threshold. A before and after slider, an edge score and a clipping warning show whether you have gone too far. It sharpens slightly soft photos, not missed focus.

Free browser tool

AI Image Sharpener: Fix Soft Photos in Your Browser

Load a photo, drag three sliders, and see the before and after live. It runs on your device, so nothing is uploaded. Honest label: it is a classic unsharp mask, not a generative model.

Sharpen a photo

Sharpen your photo

Pick a starting point, then adjust amount, radius and threshold. Slide the divider to compare. Zoom in on edges before you download.

Choose a photo or click the sample to start.

How it works

What the three sliders actually do

Amount is how hard edges are pushed

The tool blurs a copy of your photo, subtracts it from the original to find the edges, and adds a multiple of that difference back. Amount is the multiple. At 100% you add the edge detail once, at 200% twice. Past about 200% most photos start to look crunchy.

Radius decides how wide the edge boost is

Radius is the size of the blur, in pixels of the photo you loaded. A small radius, around 0.8 to 1.5 px, tightens fine detail like fabric and text. A large radius adds punch to bigger shapes but draws visible halos around high-contrast outlines.

Threshold protects flat areas and grain

Differences smaller than the threshold are left alone. Set it to 0 and every speck of noise is sharpened along with the edges. Set it to 3 or 4 and clear skies, skin and studio backdrops stay smooth while real edges still sharpen.

How to sharpen a photo in four moves

  1. 1

    Load a photo or the sample

    Choose a JPG, PNG or WebP from your device, or click the sample, a deliberately blurred test scene. The file stays in your browser.

  2. 2

    Pick a starting point

    Web and social suits feed images. Product listing is firmer. Soft-focus rescue is the ceiling, and it will show halos on most photos.

  3. 3

    Compare at full size

    Drag the divider, then zoom your browser to 100% and look at the edges. Bright outlines around dark shapes mean the amount or radius is too high.

  4. 4

    Download in the right format

    PNG keeps every pixel. JPEG and WebP give smaller files for a web upload. Sharpen after cropping and resizing, not before.

Where this helps, where it doesn't

A soft mug shot is fixable. A missed focus is not.

Sharpening works best on photos that are almost right: a product shot resized down for a listing, a phone photo with a touch of softness, an export that lost bite after compression. In those cases the edges are still in the file and the filter only needs to make them read. The result is a photo that survives the scroll. It cannot repair a photo where the focus landed on the wrong plane, or where the subject moved. The mug above is soft because the lens focused elsewhere. No slider brings that back, and pushing them hard only produces a glow around every edge.

  • Works on: slight softness, resized images, compressed exports
  • Coin flip: noisy low-light shots, raise the threshold first
  • Does not work on: missed focus, motion blur, heavy JPEG artifacts
Slightly soft photo of a white ceramic mug and a mirrorless camera on a wooden desk

Questions people ask before sharpening

Is this AI image sharpener really AI?
No, and it says so on purpose. It runs a classic unsharp mask, the same maths behind the sharpen filters in Lightroom and Photoshop. It boosts contrast along edges that already exist. It does not invent new detail the way a trained upscaler such as Topaz Photo AI or Magnific does. For a photo that is slightly soft, that is often all you need.
Is my photo uploaded anywhere?
No. The file is decoded and processed in your browser tab. Nothing leaves your device except an anonymous counter that records that the tool was used, never the image.
Is it free, and are there limits?
It is free with no signup and no watermark. The only limit is size: photos larger than 2400 px on the long side are scaled down before sharpening, to keep the sliders responsive on a phone.
Can it fix a photo that is properly out of focus or has motion blur?
Not really. Sharpening lifts contrast at edges the camera recorded. If the focus missed entirely, or the subject moved during the exposure, the edge information is gone and pushing the sliders only produces halos and crunchy texture. That is the job of a reconstruction model, or of a reshoot.
Which settings should I use for a product listing?
Start with the product listing preset (140%, 1.5 px, threshold 3), then zoom to 100% and check the edges of the object. If you see bright outlines around dark shapes, lower the amount or the radius. Sharpen last, after cropping and resizing, because resizing softens an image again.
What does the edge score mean?
It is the variance of the Laplacian of the brightness channel, a standard blur measure in image processing. A higher number means stronger edges. It depends on the photo and its size, so only compare the before and after values of the same image.
Why does sharpening make noise and grain worse?
Because noise looks like tiny edges to the filter. Raise the threshold: it tells the tool to ignore differences smaller than that many brightness levels, which leaves flat skies and skin alone while edges still sharpen.
Does it change the colors of my photo?
No. The sharpening is applied to brightness only, and the same adjustment is added to red, green and blue, so hues stay put. That avoids the colored fringes you get when each channel is sharpened separately.

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