Choose photos or drop them here
JPG, PNG or WebP — one or many. Your photos stay on your device.Amount = how strong. Radius = how wide the edges are. Threshold leaves smooth areas (skin, sky) alone, so noise is not sharpened.
About Sharpen Image
This free tool sharpens an image in your browser. It makes a soft photo look crisper: edges get a little darker on one side and a little lighter on the other, so hair, eyes, leaves and text stand out more. Drop a photo, pick a preset, and download.
The preview opens on a close-up at 100 % of the most detailed part of your photo, because sharpening is very hard to see on a photo shrunk to fit the screen. Drag the line across the picture to compare before and after.
To be honest about it: sharpening makes a soft photo crisper. It cannot bring back detail that the photo never had. A badly blurred or tiny photo will not become sharp — see below.
Everything happens in your browser: your photos are never uploaded.
Features
- Unsharp mask — the classic sharpening method used by photo editors
- Four presets — Light, Medium, Strong and Text / scan
- Amount, Radius and Threshold sliders — the preview changes as you move them
- 100 % close-up — the preview shows the most detailed part at full size, where you can really see the change
- Before and after split — drag the line across the photo to compare
- No colour fringes — only the brightness is sharpened, so edges do not get coloured halos
- Many photos at once — one click downloads them all as a ZIP
- One click to download — the file is ready before you click; it keeps its size, format and transparency
What the sliders do
| Slider | What it changes | Typical values |
|---|---|---|
| Amount | how strong the sharpening is | 50–100 % for photos, up to 200 % for text |
| Radius | how wide the sharpened edge is, in pixels | 0.5–1 px for fine detail, 1.5–2 px for a soft photo |
| Threshold | how big a difference must be before it is sharpened | 2–5 for photos, 8–12 for scans with paper texture |
Amount and Radius work together. A small radius with a high amount brings out fine detail (hair, fabric). A larger radius with a lower amount gives a soft photo more "pop".
Threshold protects smooth areas. Skin, sky and walls have small, noisy differences; with a threshold, those are left alone and only real edges get sharper.
The presets
| Preset | Amount · Radius · Threshold | Use it for |
|---|---|---|
| Light | 50 % · 0.8 px · 2 | portraits, photos that are almost sharp |
| Medium | 100 % · 1.0 px · 3 | most photos — a good start |
| Strong | 180 % · 1.4 px · 2 | soft photos, landscapes, product photos |
| Text / scan | 200 % · 1.6 px · 10 | scanned pages, photos of documents, screenshots |
A preset only sets the sliders. Move any slider after that to make it your own.
What sharpening can and cannot do
It helps with:
- Photos that are a little soft — a cheap lens, a phone in low light, a slightly missed focus
- Photos that were made smaller — resizing always softens a picture a little
- scans and photos of documents — the letters get darker and clearer
- Photos for print, which often look softer on paper than on screen
It cannot fix:
- motion blur — a shaken camera or a moving car leaves streaks, not soft edges
- A photo that is badly out of focus — the detail is not in the file
- A tiny or pixelated photo — sharpening makes the blocks harsher. To make a small picture bigger, use the Image Upscaler first, then sharpen a little.
Signs of too much: bright or dark outlines (halos) around edges, grainy skin, and "crunchy" noise in the sky. If you see them, lower the Amount or raise the Threshold.
Tip: sharpen last. Crop, resize and fix colours first, then sharpen the final size. Sharpening before you shrink a photo is mostly wasted.
How to use it
- Click Choose photos, or drop one or more photos onto the box
- Pick a preset — Medium is a good start
- Look at the close-up and drag the line to compare before and after
- Move Amount, Radius or Threshold if you want more or less
- Switch to Whole photo to see the full picture
- Click Download — one photo saves directly, many photos save as a ZIP
Frequently asked questions
How do I sharpen a blurry photo?
Drop the photo here and try Medium, then Strong. Compare in the 100 % close-up. This works well for a photo that is a little soft. A photo with strong blur or motion blur cannot be made really sharp, because the detail is not in the file.
What is an unsharp mask?
It is the standard way to sharpen a photo. The tool makes a blurred copy, finds the difference between the photo and the copy — that difference is the edges — and adds some of it back. The name comes from film darkrooms, where a blurred ("unsharp") negative was used the same way.
Why can't I see much change on the whole photo?
On a big photo shrunk to fit your screen, small edges are too small to see. That is why the preview opens on the close-up at 100 %. The file you download has the full sharpening.
Can I sharpen text or a scanned document?
Yes. Use the Text / scan preset. The higher threshold leaves the paper texture alone and makes the letters darker and crisper. For a full PDF of scanned pages, try Scan to PDF.
Can I sharpen many photos at once?
Yes. Choose or drop as many photos as you like. The same settings apply to all of them, and Download all (ZIP) saves them in one ZIP file. Only this photo saves just the one on screen.
Is the quality kept? Are my photos uploaded?
The photo keeps its full size in pixels. A PNG is saved without loss; a JPG or WebP is saved at high quality (92 %). Nothing is uploaded — the photos are changed on your device.
Related tools
- Image Upscaler — make a small picture bigger before you sharpen it
- Image Editor — brightness, contrast, crop and rotate
- Compare Images — check two versions side by side
- Image Resizer — resize first, then sharpen the final size
- Black and White Photo — a classic look for a sharpened portrait
- Bulk Image Compressor — make many photos smaller after
