Validators
Dockerfile Validator
Validate your Dockerfile syntax and instructions to build reliable container images. Get instant feedback on deprecated commands and structural issues to optimize your Docker builds.
Validate your Dockerfile syntax and instructions to build reliable container images. Get instant feedback on deprecated commands and structural issues to optimize your Docker builds.
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Tip
Always use a non-root user in your Dockerfile to improve container security and follow the principle of least privilege.
Best Practice
Order instructions from least frequently changed to most frequently changed to leverage Docker's layer caching system.
Did You Know?
Each RUN, COPY, and ADD instruction creates a new layer in your final image, impacting overall size and performance.
Q: Does this check for security vulnerabilities? A: This tool focuses on syntax and structural validation. For deep security scanning, we recommend dedicated container scanning tools.
Q: Can it validate multi-stage builds? A: Yes, the validator fully supports the syntax for multi-stage Dockerfiles including named stages and aliases.
Q: Why is my valid Dockerfile showing an error? A: Ensure you are using standard Docker instructions. If you use custom build-time variables (ARG), make sure they are declared correctly.