Catalytic WizAlert — free, private online tools

Image Compressor

Compress and resize JPG, PNG and WebP images right in your browser. Batch process, compare before and after, and download smaller files — nothing is uploaded.

Make images smaller without uploading them

Compress and resize photos and graphics for websites, email or chat. Every image is processed inside your browser — nothing leaves your device.

How to use

  1. Drop images onto the box, click it to browse, or paste with Ctrl/⌘ + V.
  2. Pick an output format and quality. Changes apply to every image instantly.
  3. Optionally set a maximum width or height to resize large photos.
  4. Drag the slider on the preview to compare original and compressed.
  5. Download images one by one, or all at once.

Tips

  • WebP is usually the smallest and works in all modern browsers.
  • A quality of 70–85% is typically indistinguishable from the original.
  • PNG is lossless, so the quality slider doesn't apply — resize or convert to WebP instead.
  • Resizing a phone photo to 1600–2000px wide often saves the most.
  • If compressing would make an image bigger, the original is kept and marked “Already optimized”.