Add your file from your device.
01Images toolImage file
Image Sharpener
Sharpen a soft or slightly blurry photo.
100% FreeBrowser-basedNo watermark
- 1UploadAdd your file from your device.
- 2Choose optionsPick the output settings you need.
- 3ProcessRun the tool in your browser.
Private by designProcessed on your device where possible.
Works on any deviceDesktop, tablet and mobile browsers.
No installationOpen the page and start working.
Always free coreUse the free plan for everyday tasks.
How to use Image Sharpener
Pick the output settings you need.
02Run the tool in your browser.
03Save the finished result.
04Your files stay private
Your work is processed locally in your browser where possible and is never added to a Vootkit upload library.
Learn more about privacySharpening does not add detail — nothing can. It increases local contrast at edges so that detail already present reads more clearly, and pushed too far it produces halos that look worse than the softness you were fixing.
What Image Sharpener does
Applies a convolution kernel that brightens each pixel relative to its neighbours, at an amount from 1 to 10 with 4 as the default. Amount 0 is a true identity — nothing changes at all.
Runs on a background worker for large images, so the page stays usable and progress is real. Results are clamped rather than wrapped, so an over-bright result stops at white instead of turning black.
Controls and behaviour
| Amount | 1 to 10, default 4 |
|---|---|
| Method | Convolution — raises local edge contrast |
| Adds detail? | No — nothing can |
| Clamping | Results stop at 0 and 255, never wrap |
| Alpha | Never sharpened — avoids edge fringing |
| Large images | Processed off the main thread |
| Best for | Slightly soft scans and web resizes |
| Cannot fix | Motion blur or a missed focus |
Detailed steps
- Add the image.
- Start at 4 and increase only if it still looks soft.
- Check the edges of high-contrast objects before downloading.
Worth knowing
Sharpen last, after resizing, never before. Resizing an already-sharpened image amplifies the halos into visible outlines, while sharpening a correctly sized image fixes exactly the softness that resizing introduced. If you can see a pale line around dark objects, the amount is too high.
Frequently Asked Questions
Can this fix a blurry photo?
No. Motion blur and missed focus destroy information, and sharpening only increases contrast around what survived. It rescues slightly soft images; it cannot rescue genuinely blurred ones, and pushing the amount up will make them look worse rather than better.
What are the halos around objects?
Over-sharpening. The kernel brightens one side of an edge and darkens the other, and at high amounts that becomes a visible outline. Reduce the amount until they disappear.
Should I sharpen before or after resizing?
After. Downscaling softens an image, so sharpening afterwards corrects exactly that. Doing it first means the resize amplifies artefacts you already created.
Does it affect transparency?
No. Alpha is deliberately left alone — sharpening the alpha channel produces visible fringing on anything with a transparent background.
Is Image Sharpener free?
Yes. The Vootkit free plan includes 5 tool runs a day. Upgrade to Vootkit Pro for unlimited daily use, an ad-free workspace and saved workflows.
Are my files uploaded?
No. Image Sharpener runs entirely in your browser — your file is processed on your own device and never sent to a server. There is nothing for us to store or delete.
Do I need to install anything?
No. Image Sharpener works in any modern browser on desktop, tablet or phone. Open the page and start.
How often can I use it? Is there a daily limit?
On the free plan you get 5 tool runs a day. When you reach the limit you'll see a prompt to upgrade, and it resets the next day. Vootkit Pro removes the cap entirely for unlimited daily use.
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This tool processes everything locally in your browser. You can disconnect from the internet after the page loads and it will still work.