Check common Dockerfile best-practice issues: multi-stage builds, non-root user, dependency caching, image tags and more, with a score and per-rule advice
FAQ
Is the pasted Dockerfile uploaded anywhere?
No. The analysis runs entirely in your browser and nothing is sent to a server. For the same reason the tool cannot read local files, so the .dockerignore check needs your own confirmation.
Which issues should I fix first when the score is low?
Start with error-level findings such as a missing FROM or an unpinned base image tag. Then follow the advice to adopt a multi-stage build, declare a non-root user, and copy dependency manifests before source code for better caching.
All data is processed locally in your browser. Nothing is uploaded.