Dockerfile Linter
Lint a Dockerfile for common best-practice issues.
About the Dockerfile Linter
Paste a Dockerfile and get instant feedback on common issues: unpinned base images, missing USER instruction, shell-form CMD/ENTRYPOINT, apt-get cache hygiene, and more.
Examples
Unpinned image
FROM node:latestOutput
YAMLWarning: avoid latest tagKeyboard shortcuts
- Copy the main outputCtrl / ⌘ + Shift + C
- Download the resultCtrl / ⌘ + S
- Share this toolCtrl / ⌘ + Shift + S
- Reset the inputsAlt + R
- Open the tool search paletteCtrl / ⌘ + K
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Frequently asked questions
Read more
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A practical guide to opening a source archive, tracing dependencies, inspecting syntax trees and exporting edited files without uploading a repository.
Version 1.0.0 · Updated 2026-08-06 · Runs entirely in your browser