Image Sharpener
Make soft or slightly blurry photos crisp – unsharp mask with radius and threshold, edge-only smart sharpening and deblur – and check every detail at 100% zoom.
- Smart sharpen
- Deblur
- Amount, radius, threshold
- No upload
How to sharpen a photo
- Add a photoDrop an image, choose a file, paste one with Ctrl+V or try the sample. It stays on your device.
- Choose how to sharpenPick Gentle, Standard, Strong, Text, Deblur or Web, then fine-tune amount, radius and threshold. Turn on 100% zoom to judge fine detail.
- Compare and downloadDrag the compare slider to see before and after, then download in full resolution.
Starting points
| Photo | Amount | Radius | Threshold |
|---|---|---|---|
| Portraits | 40–80% | 1–1.5 px | 3–6 (smart on) |
| Landscapes and buildings | 80–150% | 1–2 px | 0–3 |
| Text, receipts, documents | 150–250% | 0.8–1.2 px | 0 |
| After resizing for the web | 50–80% | 0.5–0.8 px | 0 |
| Slightly out of focus | Deblur 8–15 passes, blur size 1.5–2.5 px | – | – |
Too much sharpening shows as bright halos along edges and grainy flat areas – zoom to 100% and back off if you see them.
Frequently asked questions
Can this fix a blurry photo?
It can noticeably improve slightly soft or out-of-focus photos. Choose Deblur, which uses deconvolution to reverse a small amount of blur, and match “Blur size” to how soft the photo is. Heavy motion blur or badly out-of-focus photos can’t be fully recovered by any tool.
What do amount, radius and threshold mean?
Amount is how strong the sharpening is. Radius is how wide the edges it works on are – small values (0.5–1.5 px) for fine detail, larger for overall punch. Threshold skips smooth areas whose contrast is below the value, so skin and sky don’t get grainy.
What is smart sharpen?
Smart sharpen only sharpens edges – found with an edge-detection filter – and leaves flat areas alone, which avoids noise and halos. Tick “Show where it sharpens” to see the edge mask.
Why sharpen brightness only?
Sharpening each colour separately can create coloured fringes along edges. Sharpening only the brightness gives crisp detail without colour artefacts – it’s on by default.
When should I use the Web preset?
After shrinking a photo for a website or social media, a light, small-radius sharpen restores the crispness lost in resizing.
Why should I check at 100% zoom?
On a scaled-down preview, sharpening is hard to judge. 100% zoom shows the real pixels so you can spot halos or noise before you download.
Are my photos uploaded?
No. All processing happens in your browser.
Is the image sharpener free?
Yes, completely free with no sign-up and no watermark.
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