Dockerfile Linter
Lint Dockerfiles for unpinned images, secrets in ENV, running as root, apt-get mistakes and more. Free and private: runs in your browser.
Paste a Dockerfile to get hadolint-style findings (DL3006, DL3008…) for security, size and reproducibility.
Runs entirely in your browser. Nothing you paste is uploaded or stored.
Use cases
- Find a syntax error before the build or deploy fails.
- Check config files in code review.
- Learn the rules your linter enforces.
Frequently asked questions
Why should containers not run as root?
If the app is compromised, root inside the container makes escaping to the host or other containers far easier. Add a USER instruction.
Is the Dockerfile Linter free?
Yes. It is free with no sign-up, and it runs entirely in your browser, so your input is never uploaded or stored.
What should I do with the issues it reports?
Fix high-severity items first; they usually break builds or deployments. Lower-severity items are style and best-practice suggestions.
Related tools
Checking one snippet is a start. Scan your whole repository for free with CodeInspector.