Free Image Sharpener

The Image Sharpener is a free online tool that sharpen blurry images online using unsharp masking. before/after comparison view. It runs entirely in your browser with no installation or sign-up needed.

An unsharp mask (convolution kernel) enhances edges and fine detail in the image.

Yes — use the split-view comparison to see the effect.

Yes, completely free.

Absolutely. The Image Sharpener processes everything client-side in your browser. No data is uploaded to or stored on any server. Your content remains private on your device at all times.

Yes, the Image Sharpener is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.

No account or registration is needed. Simply open the Image Sharpener in your browser and start using it immediately. There are no sign-up walls or usage restrictions.

The Image Sharpener supports common image formats including PNG, JPG/JPEG, WebP, and GIF. Some features may also support SVG and BMP depending on the specific tool.

Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.

The Image Sharpener works in all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. For the best experience, use the latest version of your preferred browser.

Sharpening and unblurring sound the same but work differently. This tool sharpens by running an unsharp mask, a 3x3 convolution that amplifies the contrast between a pixel and its neighbors so edges, text, and textures look crisper. It boosts detail the image already contains, improving perceived focus. True unblurring (deconvolution) tries to mathematically reverse motion blur or a missed focus by reconstructing lost information, which is far harder and often needs AI models. The key limit is that sharpening cannot add detail the camera never captured, so it will not rescue a heavily out-of-focus or smeared shot. It works best on photos that are only slightly soft. Upload a marginally blurry image and drag the comparison slider to see how much crispness the unsharp mask recovers.

Start low and increase gradually while watching the before/after slider. This tool offers three presets: Subtle (around 0.3) for portraits and only slightly soft photos, Medium (around 0.7) as a balanced default for general web images and product shots, and Strong (around 1.2) for screenshots, diagrams, or scans where crisp edges matter more than smooth tone. A Custom slider runs from 10% to 200%, but values above 100% apply extreme sharpening and commonly introduce halos, noise, or jagged artifacts. The telltale signs of overdoing it are bright outlines around high-contrast borders and speckling in smooth areas like skin or sky. If you see those, ease the strength back down. The goal is an image that looks naturally in focus rather than obviously processed. Dial in the strength and judge the result on the live comparison view.

The sharpened result is always saved as a PNG, named after your original file with a _sharpened suffix. PNG uses lossless compression, so it preserves every pixel without quality loss, but that also means a sharpened JPG usually grows in file size compared with the original. Sharpening itself adds to this because it increases edge contrast and high-frequency detail, which lossless formats store faithfully rather than discarding. PNG is the safe default since it keeps transparency and avoids re-introducing JPEG compression artifacts on top of the sharpened edges. If you need a smaller file afterward, run the downloaded PNG through a separate image compressor or format converter to produce a leaner JPG or WebP. Sharpen your image here first, then compress the PNG result as a final step if file size matters.

Yes. The tool preserves the original transparency, or alpha channel, when it sharpens your image. The unsharp mask only adjusts the red, green, and blue color channels to enhance edges and detail, while each pixel's alpha value is carried straight through unchanged. That means transparent backgrounds, logos, icons, and cut-out product shots stay transparent after sharpening, with no white or black fill appearing behind them. Pixels along the very edge of the image are also copied through as-is rather than processed, which avoids odd artifacts at the border. Because the output is saved as a PNG, that transparency is retained in the downloaded file too, since PNG supports an alpha channel. Upload a transparent PNG and the sharpened download will look crisper while keeping its see-through areas intact.

There is no server-imposed file size cap, because nothing is uploaded. The Image Sharpener reads your file directly from your device and processes it entirely in memory using the HTML canvas, so there is no upload queue or storage limit to bump against. The practical limit is your own hardware. The unsharp mask works pixel by pixel across the whole image, so very large or high-resolution photos take longer to process on slower machines and use more memory in the browser tab. On a modern computer typical web and phone images sharpen almost instantly, while very large scans may need a few seconds. If a huge image feels sluggish, resizing it first will speed things up. Drop in your image and the preview re-renders automatically each time you change the strength, with no size restriction from our side.