Image Optimize — shrink images with ImageMagick

This skill makes a smaller copy of a JPEG, PNG, or WebP with ImageMagick and always leaves the original file in place. Use it when an image is larger than where it is going: a page, an attachment, or a thumbnail.

The core operation resizes so the longest side is at most 1600 pixels (shrink-only), bakes in the EXIF orientation, strips metadata, and writes a new file at a sensible quality — 82 for JPEG, 80 for WebP. The skill shows how to pick the right binary once (magick on ImageMagick 7, convert on 6) and reuse it, and how to verify the result with identify and ls -l before keeping it.

The gotchas are the point. mogrify overwrites the file you name, so these commands use magick/convert to a new file instead. -auto-orient must run before -strip, or a phone photo can come out sideways once its orientation tag is gone. The resize geometry must stay quoted — an unquoted > is a shell redirect.

One honest limit: a file that is already small can grow when it changes format. The skill's rule is to compare sizes and keep the original when the new file is larger.