Smaller Docker images pull faster, deploy quicker, and shrink your attack surface. Before optimizing, measure: our free Docker Image Size Checker shows the compressed size and per-architecture layers of any public image and lets you compare tags.
Start with a smaller base image
Switching from a full OS image to an alpine or slim variant often cuts hundreds of megabytes. Compare tags like node:20 versus node:20-slim or node:20-alpine to see the difference instantly.
Use multi-stage builds and fewer layers
Build your app in one stage and copy only the artifacts you need into a clean final stage. Combine related RUN commands and clean package caches in the same layer so they don’t bloat the image. Re-check the size after each change with the Docker Image Size Checker.