When you try to optimize the size of an image it is possible to display the size of every layers :
docker history <image-id>
For example :
(ins)❯ docker history 7383c266ef25
IMAGE CREATED CREATED BY SIZE COMMENT
7383c266ef25 12 days ago CMD ["nginx" "-g" "daemon off;"] 0B buildkit.dockerfile.v0
<missing> 12 days ago STOPSIGNAL SIGQUIT 0B buildkit.dockerfile.v0
<missing> 12 days ago EXPOSE map[80/tcp:{}] 0B buildkit.dockerfile.v0
<missing> 12 days ago ENTRYPOINT ["/docker-entrypoint.sh"] 0B buildkit.dockerfile.v0
<missing> 12 days ago COPY 30-tune-worker-processes.sh /docker-ent… 4.62kB buildkit.dockerfile.v0
<missing> 12 days ago COPY 20-envsubst-on-templates.sh /docker-ent… 3.02kB buildkit.dockerfile.v0
<missing> 12 days ago COPY 15-local-resolvers.envsh /docker-entryp… 336B buildkit.dockerfile.v0
<missing> 12 days ago COPY 10-listen-on-ipv6-by-default.sh /docker… 2.12kB buildkit.dockerfile.v0
<missing> 12 days ago COPY docker-entrypoint.sh / # buildkit 1.62kB buildkit.dockerfile.v0
<missing> 12 days ago RUN /bin/sh -c set -x && groupadd --syst… 113MB buildkit.dockerfile.v0
<missing> 12 days ago ENV PKG_RELEASE=1~bookworm 0B buildkit.dockerfile.v0
<missing> 12 days ago ENV NJS_RELEASE=2~bookworm 0B buildkit.dockerfile.v0
<missing> 12 days ago ENV NJS_VERSION=0.8.4 0B buildkit.dockerfile.v0
<missing> 12 days ago ENV NGINX_VERSION=1.25.5 0B buildkit.dockerfile.v0
<missing> 12 days ago LABEL maintainer=NGINX Docker Maintainers <d… 0B buildkit.dockerfile.v0
<missing> 12 days ago /bin/sh -c #(nop) CMD ["bash"] 0B
<missing> 12 days ago /bin/sh -c #(nop) ADD file:4b1be1de1a1e5aa60… 74.8MB