Docker Compose Validator | Compose File Checker

Docker Compose validator that checks compose.yaml against the Compose spec and finds port clashes, undeclared volumes and depends_on cycles. Free.

Also known as: docker compose validator · docker compose validator online · validate docker compose file · docker compose checker · docker compose yaml validator · compose file linter · docker compose syntax checker · docker-compose.yml validator

devops and infrastructure tools

xml and yaml tools

validators

Compose YAML Input

Validation Results

Errors, warnings and a port map of your services will appear here

About Docker Compose Validator

A Docker Compose validator checks a compose.yaml or docker-compose.yml before you run docker compose up, so a missing volume or a port clash does not surface as a container that will not start. It validates every key against the Compose Specification, then cross-checks the services against each other: dependencies, networks, volumes, secrets and published ports.

Key Features

Validates top-level and service keys against the official Compose Specification, with did-you-mean suggestions for typos like depend_on or enviroment
Finds services that use a network, volume, secret or config never declared at the top level, and declared ones nothing uses
Detects host-port collisions between services and fixed host ports on services scaled to more than one replica
Checks depends_on for missing services, cycles and service_healthy conditions on services without a healthcheck
Flags unpinned images, Docker socket mounts, privileged containers, literal passwords in environment and databases published on every interface
Shows a port map of every service with its image, host to container ports and dependencies

Use Cases

Check a local stack of a Next.js app, Postgres and Redis before handing the compose file to a new hire
Review a docker-compose.yml from a GitHub repo before running it on a laptop or a us-east-1 EC2 host
Find out which service already holds port 8080 when docker compose up fails with port is already allocated
Audit compose files for hardcoded secrets and exposed database ports ahead of a SOC 2 review
Clean up an old Compose v1 file by removing the obsolete version key and legacy links

Supported Formats

compose.yaml

compose.yml

docker-compose.yml

docker-compose.yaml

Compose Specification

Related Keywords

docker compose validator

docker compose validator online

validate docker compose file

docker compose checker

docker compose yaml validator

compose file linter

docker compose syntax checker

docker-compose.yml validator

How do I validate a docker-compose.yml file?

Run docker compose config in the project folder: it parses the file, fills in variables from .env and stops on the first schema error. Paste the file here when you do not have Docker at hand, or to get every problem at once with line numbers, including issues docker compose config accepts but that fail later, such as two services publishing the same host port.

Your compose file stays in your browser

Validation runs entirely in your browser with no upload, so passwords, hostnames and image names in your compose file never leave your machine.

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Frequently asked questions

What is Docker Compose Validator used for?

Docker Compose validator that checks compose.yaml against the Compose spec and finds port clashes, undeclared volumes and depends_on cycles. Free.

Is Docker Compose Validator free to use?

Yes. Docker Compose Validator is completely free with no usage limits, and there is no paid tier required to use it.

Do I need an account to use Docker Compose Validator?

No. Docker Compose Validator works immediately in your browser with no signup, login, or email address required.

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