Image Sharpener

A photo taken on the go can turn out slightly blurry. A scanned document may have soft edges. An image upscaled from a small original can look fuzzy. In all these cases, image sharpening is a practical fix.

This tool uses the unsharp-mask technique — one of the most widely used sharpening algorithms in image processing. Despite the counterintuitive name, unsharp masking works by subtracting a blurred version of the image from itself to amplify edge contrast. Technically, it applies a 3×3 convolution kernel across every pixel, weighting the center pixel more heavily than its neighbors to accentuate transitions between light and dark areas.

You control the intensity with a slider from 0% (no effect) to 200% (aggressive sharpening). The real-time Canvas preview updates instantly as you drag, so you can find the sweet spot before over-sharpening introduces unwanted ringing artifacts. All processing runs locally via the Canvas API — no image data is ever sent to a server, making the tool safe for confidential or sensitive images.

Supports PNG, JPEG, and WebP input, and exports in the matching format. Useful for blog post thumbnails, product photos on e-commerce sites, screenshots in presentations, and any image that needs a quick clarity boost.