How it works
Your images are drawn onto an off-screen canvas in your browser and re-encoded at the quality and size you choose. Because everything runs locally with JavaScript, your photos are never sent to any server β unlike most online compressors that upload your files first.
Quality vs. file size
Lower quality means a smaller file. For photos, 70β85% JPG is usually indistinguishable from the original while cutting file size dramatically. PNG stays lossless (best for logos and transparency) but is larger. WebP often beats both for the same quality.
Resizing
Set a max width or height to shrink large photos β a 4000 px phone photo rarely needs to stay that big for the web or email. Aspect ratio is always preserved, so images never stretch.
Processing happens entirely in your browser. Very large batches are limited only by your device's memory.