Can sharpening recover missing detail?
No. Unsharp masking increases contrast around existing edges. It can improve perceived crispness, but it cannot reconstruct focus, texture or detail that was never captured.
Adjustable unsharp mask
Sharpen Images Online
Tune edge contrast for one image or a batch, inspect the result and export at full source resolution.
Last updated: August 2026
3 Controls
Amount / Radius / Threshold
6 Presets
Starting Points
Batch ZIP
Multiple Images
Private
No Uploads
Drop your image here
JPG, PNG, WebP, GIF, BMP, AVIF, HEIC or TIFF
Your file never leaves this device
How to sharpen an image
01
Choose single or batch mode
Use single mode for close inspection or batch mode to apply shared settings to several files.
02
Choose a preset or tune controls
Adjust Amount, Radius and Threshold, with luminance-only sharpening enabled by default.
03
Inspect edges carefully
Zoom, pan and compare the original to check for halos, noise and unnatural outlines.
04
Choose a format and export
Download JPEG, PNG or WebP, or package batch results into a ZIP.
What the sharpener actually does
Real unsharp-mask calculation
The tool subtracts a blurred copy from the source and adds a scaled edge delta back.
Six starting presets
Subtle, Web Photo, Portrait, Landscape, Text and Screenshot, and Strong set different control combinations.
Responsive preview
The working image is capped at 1400 pixels on its longest side, while export recomputes at full source resolution.
Luminance-only option
Brightness-derived sharpening reduces colored edge fringing and is enabled initially.
Single and batch modes
Single mode provides zoom and comparison; batch mode applies common settings and supports ZIP export.
New encoded files
JPEG, PNG and WebP outputs do not preserve source metadata, animation or original encoded bytes.
Common image-sharpening mistakes
Expecting focus recovery
Sharpening cannot recreate missing optical detail.
Using too much Amount
Strong edge contrast can produce obvious bright and dark outlines.
Using a wide Radius on text
Broad halos can make lettering look less natural.
Sharpening before the final resize
A later resize changes the edge grid and can weaken or distort the effect.
Judging only at fit-to-screen size
Halos and noise often become visible only when zoomed.
Expecting original metadata
All output formats are newly encoded through Canvas.
Why use ImgTweak?
✓Three independent controls
✓Six content presets
✓Luminance-only option
✓Full-resolution export
✓Batch ZIP download
✓No uploads or account required
Frequently asked questions
What do Amount, Radius and Threshold control?
Amount controls strength, Radius controls the width of the edge effect, and Threshold prevents low-contrast differences from being sharpened. Excessive values can create bright or dark halos.
What does luminance-only sharpening do?
It calculates the sharpening delta from brightness and applies the same delta to red, green and blue. This reduces color fringing. The option is enabled by default but can be turned off.
Is the preview full resolution?
No. The working preview is capped for responsive adjustment. Download processing runs again against the source image's full resolution.
What formats can I export?
The tool exports PNG, JPEG or WebP. JPEG and WebP start at quality 92 and provide a quality control; PNG does not use that lossy-quality setting.
How does batch mode work?
Several browser-decodable images can share one set of sharpening and output settings. You can download items individually or package all completed outputs into a ZIP.
Are metadata and animation preserved?
No. Canvas-based export creates new still-image files and does not preserve EXIF metadata, ICC data or animated frames.
Are my images uploaded?
No. Loading, preview processing, full-resolution sharpening, encoding and ZIP creation happen locally in your browser.
Ready to sharpen your image?
Choose single or batch mode above, inspect the edges and export the result.