How does image compression work?
This tool leaves every image in its own format (“Original” is selected) and re-encodes it. For lossy formats such as JPG and WebP the quality setting decides the file size; for PNG a lossless oxipng optimisation is applied.
Which quality should I pick?
- 85–90: nearly lossless look, good for print and product photos.
- 75–80: a good balance for web and blog images.
- 60–70: small previews and pages that must load very fast.
Reduce the dimensions too
Pixel count affects file size more than anything else. Uploading a 4000-pixel image that is shown at 800 pixels wastes bandwidth; limit the width in the Resize section.
Pick a better format
At the same visual quality WebP and AVIF are usually smaller than JPG and PNG. For website use, consider changing the output format.