Fastwebly
image tools

Resize Image By File Size

Shrink images to fit under a target file size. Supports PNG, JPEG, and WebP.

Resize Image by File Size
Shrink your image to fit under a target file size while preserving dimensions as much as possible.
Click or drop an image
Target File Size
KB

Upload an image to see a live preview.

Features

  • Resize to a target file size in kilobytes
  • Live preview updates as you adjust the target size slider
  • Preserve aspect ratio and maximum dimensions possible
  • Support for PNG, JPEG, and WebP output formats
  • Download the compressed image instantly

How it works

Upload an image, set your target file size with the slider, and choose the output format. The tool uses binary search to find the optimal scale factor that fits under your target — balancing dimensions and quality. Everything happens locally in your browser using the Canvas API.