Squoosh compares an original image with compressed output in real time. Resize controls and multiple codecs make it easy to see exactly how much quality a smaller file is costing.
What it does
A split preview exposes the original and processed image while controls adjust dimensions, colour and codec settings. File size updates immediately, so optimisation becomes a visual decision rather than a blind preset.
Why it is useful
The processing happens locally and the interface teaches as it works. You can compare WebP, AVIF, JPEG and PNG behaviour without installing command-line encoders or uploading private images to a conversion service.
How to use it
Resize before compressing, zoom into detailed areas and lower quality until artefacts become visible, then step back slightly. Keep the original elsewhere; Squoosh is an output tool, not an asset library.
Things to know
- Very large images can be slow on modest devices.
- Batch workflows are limited.
- Codec support in target browsers still needs checking.