Website images too large? Compress to WebP or AVIF on this computer

Image Optimizer is for article images, landing assets, and pictures inside installers. You do not upload them to an online compressor, and there is no 5 MB upload cap. It runs on macOS and Windows. Free quota is 300 images per calendar month.

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When does this workflow fit?

Blog or docs images slow down first paint.
A hero image should become WebP or AVIF without looking broken.
A desktop app or game ships a pile of PNG / JPEG.
One folder mixes jpg, png, and gif, and you want a single pass.

Lab note: a 6-file mixed set went from 3.19MB to 0.95MB, about −70.3% (RC on 2026-08-22, not your site average).

Suggested steps

Open Plans and pick Convert to WebP, or set the target to AVIF or JPEG XL.
If each file needs a budget, turn on Target size (for example 200 KB for article art).
Drop images/ or assets/ and click Optimize. Subfolders are kept when possible.
Use before/after compare on hero images so type and edges still hold.
If a result grows, the negative-opt guard keeps the original.

You can turn off format conversion and only emit extra sizes or a watermark. The main file then keeps original bytes. See plans.

Online compressor or desktop app?

Need	Better fit
One small file and you accept uploads	An online tool
Whole folders, large files, AVIF / JXL, visual compare	Image Optimizer
Assets that must not leave the machine	Image Optimizer
An export folder that should shrink by itself	Watch folders

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