🍋 Image Tools

Sharpen Image

Sharpen images using an unsharp mask convolution kernel.

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Sharpening Amount

Subtle Strong

Output Format

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About Sharpen Image

Sharpen JPEG, PNG, and WebP images using a convolution kernel. Enhance edges and details in slightly blurry or soft photos. Adjust the sharpening amount from subtle to strong.

How It Works

A 3x3 unsharp mask convolution kernel is applied to every pixel. Unlike CSS filters (which lack a sharpen option), this uses direct pixel manipulation via getImageData and putImageData. Each pixel's value is calculated by weighing it against its neighbors.

Step by Step

1 Upload one or more images (JPEG, PNG, or WebP)
2 Adjust the sharpening amount slider (1-100%)
3 Click Sharpen to process your images
4 Download the sharpened results

Tips

20-40% is usually enough for slightly soft photos.
Higher values (60-100%) are useful for intentionally blurry or out-of-focus images.
Over-sharpening creates visible halos around edges — use moderation.
Sharpening works best on images with clear edges and details.

Frequently Asked Questions

Why not use a CSS filter for sharpening?

CSS filters don't include a sharpen filter. Sharpening requires a convolution kernel applied to individual pixels.

What is an unsharp mask?

Despite the name, unsharp masking sharpens images by enhancing edge contrast. It subtracts a blurred version from the original to emphasize details.