Dockerfile Validator & Linter
Lint your Dockerfile against production best practices. Catches insecure defaults (root user, :latest tags), wasteful patterns, and missing directives (HEALTHCHECK, USER, WORKDIR) with a 0-100 quality score.
About the Dockerfile Validator & Linter
Lint your Dockerfile against production best practices. Catches insecure defaults (root user, :latest tags), wasteful patterns, and missing directives (HEALTHCHECK, USER, WORKDIR) with a 0-100 quality score.
Dockerfile Validator & Linter is a free browser-based tool on QuickFnd. Lint your Dockerfile against production best practices. Catches insecure defaults (root user, :latest tags), wasteful patterns, and missing directives (HEALTHCHECK, USER, WORKDIR) with a 0-100 quality score. No installation or account required — runs entirely in your browser on desktop and mobile.
- Type
- Tool
- Runs in
- Your browser — no account, no install
- Price
- Free
- Privacy
- Inputs stay on your device unless the tool says otherwise
Frequently asked questions
It runs against 14 production-grade rules: :latest tag usage, multi-stage naming, apt-get without --no-install-recommends or cleanup, curl-pipe-to-shell anti-pattern, ADD with URL, USER root, missing USER directive, missing WORKDIR, missing HEALTHCHECK, too many RUN layers, "COPY . ." before dependency install, relative WORKDIR paths, and single-FROM sanity.
Start at 100 points. Each error subtracts 25, each warning subtracts 8, each info hint subtracts 3. Clean Dockerfiles score 90-100. Production Dockerfiles usually land 75-90 after one pass.
No. The entire parser and rule engine runs in your browser. Your Dockerfile never leaves your device.
Because copying everything early invalidates the Docker layer cache on every file change. The standard pattern is: COPY the dependency manifest first, RUN install, then COPY the rest of your source.
Yes — USER must not be root, :latest must be pinned, curl-pipe-to-shell is flagged, and ADD with URLs is flagged. For deeper image scanning, use Trivy or Snyk after the build.
The badges at the top of the score panel show whether your Dockerfile has each directive. Green means present; red means missing. All three are optional from Docker's point of view but expected by orchestrators like Kubernetes.
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