Free, browser-based utilities for everyday developer workflows

Dockerfile Linter / Best-Practice Checker

Detect common Dockerfile issues such as unpinned base images, root-user containers, missing multi-stage builds, and oversized copy steps.

  • Flags risky patterns before CI or image scanning catches them later.
  • Highlights stage count, base image pinning, and common package-install cleanup issues.
  • Useful for app teams, platform teams, and code review checklists.

Use cases

Lint a Dockerfile Before Build

Explore more in the Use cases library.

Dockerfile input

Summary

Stages-
Errors-
Warnings-
Infos-

Findings

How to use Dockerfile Linter / Best-Practice Checker

Paste a Dockerfile and run the checker. The tool highlights likely review issues such as base image pinning, root users, multi-stage opportunities, and cache-cleanup gaps in package installation steps.

Common use cases

Developers use it before opening a pull request, reviewers use it to scan for container hardening gaps, and platform teams can use it as a fast browser-side guardrail before more formal CI policies run.

Why run this in your browser?

The linting runs locally in your browser. Your Dockerfile stays on your machine, which is useful when images, registries, or internal file layouts should not be pasted into external services.