docker-image-compare

docker-image-compare shows how much layer data a set of public Docker images have in common. Add two or more images and pick a platform, and it lists each image's size, how much of it is shared with the others and how much is its own. A diagram connects the images that share layers; a 100% link means one image is built entirely on top of the other.

A registry, like a host's disk, stores each layer once, so images built on the same base take less space together than their sizes add up to. That matters on a small server that has to keep several images around. You can check, for example, whether python:3.12-slim and node:20-slim share more than their -bookworm versions before choosing which to run.

It reads the manifests from the registry and doesn't pull anything. Sizes are compressed layer sizes, as the registry stores them. A public instance runs at dic.vyrtsev.com.