Dockerfile Linter

Lint Dockerfiles for common issues, best practices, and security concerns. Get actionable suggestions to improve your container builds.

Frequently Asked Questions

It checks for common issues like using :latest tags, multiple consecutive RUN commands that should be combined, using ADD instead of COPY, missing WORKDIR, missing USER instruction, and more.
No β€” this is a lightweight browser-based linter that catches the most common Dockerfile anti-patterns. For comprehensive CI/CD linting, use Hadolint or similar tools.
Issues are categorized as Error (likely bugs or security concerns), Warning (best-practice violations), and Info (suggestions for improvement).
The :latest tag is mutable and can change unexpectedly, leading to unreproducible builds. Always pin to a specific version or digest for deterministic builds.
Each RUN instruction creates a new image layer. Combining related commands with && reduces the number of layers and final image size, especially for apt-get install chains.