Free Docker Compose Validator Tool — Lint, Format and Convert

Docker Compose Validator & Formatter

Validate, lint & format docker-compose.yml — or convert docker run to Compose  ·  Ctrl+Enter to run

docker-compose.yml 0 lines
Show:
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Paste your docker-compose.yml and click Validate

Tip: press Ctrl+Enter to validate instantly

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            docker run command
          

          
          

            
            
            
          

          

        


        
        

          

            
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Paste a docker run command and click Convert

            
Supports: -p -v -e –env-file –name –network –restart –memory –cpus –entrypoint –health-cmd and many more

          

          

            

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      Built by VahaC
      — 100% client-side, no data sent anywhere.
    

  






This docker compose validator tool catches YAML errors, bad practices, and potential security issues in your docker-compose.yml files before they become runtime headaches. Whether you are a homelab enthusiast writing your first stack or an experienced self-hoster managing dozens of services, this docker compose validator tool gives you instant, actionable feedback — right in the browser.





No sign-up. No server. Nothing leaves your machine.










What This Docker Compose Validator Tool Does





This docker compose validator tool covers three main workflows in a single interface:





🔴 Error detection — Finds structural problems that will prevent your stack from starting at all:





    

  • YAML syntax errors with the exact line number
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  • Services missing both image: and build:
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  • Invalid port formats (malformed host/container mappings)
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  • depends_on referencing a service that doesn’t exist in the file
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  • Named volumes used in a service but not declared at the top-level volumes: block
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🟡 Warnings — Catches real-world ops mistakes that won’t stop the stack but will bite you later:





    

  • Deprecated version: field (removed in Compose Spec v2)
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  • Images using :latest or no tag — bad for reproducibility
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  • Missing restart: policy — containers won’t auto-recover after reboot
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  • Ports bound to all network interfaces (80:80) instead of 127.0.0.1:80:80
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  • network_mode: host and privileged: true security risks
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  • Potential secrets exposed in environment: variables (PASSWORD, SECRET, TOKEN, API_KEY, etc.)
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  • Deprecated links: usage
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🔵 Hints (off by default, enable with one click) — Best-practice nudges:





    

  • No container_name — makes docker exec and log hunting harder
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  • No healthcheck — prevents depends_on: condition: service_healthy from working
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  • No resource limits — a runaway container can crash the whole host
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  • No logging config — container logs will grow forever without rotation
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Each issue links directly to the official Docker Compose reference documentation, so you can understand the rule, not just follow it.





🔄 docker run → Compose converter — paste a docker run command (including multi-line backslash-continued ones) and get a ready-to-use docker-compose.yml back. The converter handles over 30 flags: -p, -v, -e, --env-file, --name, --network, --restart, --memory, --cpus, --entrypoint, --health-cmd, --log-driver, --ulimit, --security-opt, combined short flags like -dit, and many more.










How to Use the Docker Compose Validator Tool





Validate tab:





    

  1. Paste your docker-compose.yml into the left panel (or click Example to load a demo)
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  2. Click ✅ Validate (or press Ctrl+Enter)
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  3. Filter results by level — 🔴 Errors, 🟡 Warnings, 🔵 Hints
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  4. Click the 📖 docs tag on any issue to open the official reference
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  5. Copy or download the auto-formatted output from the right panel
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Convert tab:





    

  1. Paste your docker run command — multi-line backslash continuation is supported
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  2. Click 🔄 Convert
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  3. Review any conversion notes in the warning panel
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  4. Click ✅ Validate to send the result directly to the validator
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Why YAML Errors Are So Common in Docker Compose





Docker Compose files are deceptively easy to write incorrectly. Indentation is significant, port values like 80:80 must be quoted (otherwise YAML parses them as a mapping), and the Compose Spec has evolved — many guides online still include the deprecated version: field or use links: instead of named networks.





The docker compose validator tool solves this by running validation locally in your browser, so you can iterate without deploying to a server. If you’re new to Docker, the guide Docker for Beginners — Containers, Images, Volumes and Compose is a solid starting point before you dive into complex stacks. For security-conscious self-hosters, the post on Docker hardened images for self-hosting pairs well with the warnings this tool surfaces.










Practical Use Cases





🏠 Homelab stack audits — Run your entire docker-compose.yml through the docker compose validator tool before upgrading a stack on your home server. Catch a missing volume declaration or a forgotten restart: unless-stopped before your media server disappears after the next power cut.





🔐 Security review before publishing — Planning to share a Compose file? The secret-in-env warning catches hardcoded credentials you may have forgotten. Combined with Vaultwarden on Docker, you can move those secrets to a proper vault.





🔄 Migrating from docker run scripts — Many self-hosted apps are documented with docker run commands. Paste them into the converter, get clean Compose YAML, validate it immediately, and you’re done.





🧑‍🏫 Learning Compose best practices — The hint layer with doc links is a practical way to learn. Enable hints, run the tool against your existing stacks, and read the linked docs when something is flagged.





📦 Managing complex multi-service stacks — Tools like Portainer and WordPress + MariaDB on OMV involve multiple services with dependencies. The docker compose validator tool verifies that all depends_on references exist and that named volumes are properly declared.










Privacy and Data Policy





    

  • ✅ 100% free — no registration, no limits
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  • ✅ No data storage — your YAML never leaves the browser
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  • ✅ No ads in output — no watermarks, no tracking pixels
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  • ✅ Client-side only — the only external request is loading the js-yaml library from cdnjs on first load
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The formatting and validation all run in your browser using the MIT-licensed js-yaml 4.1.0 library. You can inspect the source or run it offline after the initial load.










More Tools from VahaC





Browse all utilities at vahac.com/tools. If you work with JSON as well as YAML, the JSON Formatter and Validator follows the same zero-backend philosophy and is a natural companion tool.