What does this Docker Compose validator check?

It checks for valid YAML syntax, the presence of the required 'services' key, that each service has an 'image' or 'build' directive, valid port mapping formats, valid volume mount syntax, valid environment variable formats, correct depends_on references, and common misconfigurations.

Does this replace 'docker compose config'?

This tool provides instant browser-based validation without needing Docker installed. It catches many common issues but does not replace the full validation that 'docker compose config' performs, which also resolves environment variables, extends, and verifies image availability.

Why does it warn about the 'version' key?

Docker Compose V2 (the 'docker compose' plugin) no longer requires or uses the 'version' key. It was used in the legacy docker-compose (with hyphen) to select the file format version. Modern Docker Compose ignores it, so it can be safely removed.

Is my Docker Compose file sent to a server?

No. All parsing and validation happens entirely in your browser. Your compose file content never leaves your device.

What port formats are considered valid?

Valid port formats include: '8080' (container port only), '8080:80' (host:container), '127.0.0.1:8080:80' (IP:host:container), '8080-8090:80-90' (port ranges), and optional protocol suffix like '8080:80/tcp' or '8080:80/udp'.

Does it validate Docker image names?

This tool checks that each service has either an 'image' or 'build' key defined, but it does not verify that the specified image exists in a registry. Use 'docker pull' to verify image availability.

CalcHive

Docker Compose Validator

New

Validate Docker Compose YAML files for common issues. Checks services, ports, volumes, environment variables, depends_on references, and more.

Docker Compose File (YAML)

Validation results will appear here...

How to Use Docker Compose Validator

Paste your Docker Compose YAML into the text area.
Click "Validate Docker Compose" to check for issues.
Review errors (red) and warnings (yellow) in the results.
Fix the reported issues in your compose file.
Re-validate until all checks pass.

Why Validate Docker Compose Files?

Docker Compose files define multi-container applications with services, networks, and volumes. A small typo or misconfiguration can prevent your entire stack from starting. Validating your compose file before running 'docker compose up' helps catch issues early.

Common mistakes include missing image/build directives, invalid port mappings (e.g., ports above 65535), referencing services in depends_on that do not exist, and incorrect volume mount syntax. This tool checks for all of these and more, giving you confidence before deployment.

Frequently Asked Questions

Related Tools

YAML Validator

Validate and debug YAML syntax

JSON Schema Validator

Validate JSON data against a JSON Schema

.env File Parser & Converter

Parse .env files to JSON, YAML, Docker, shell

Was this tool helpful?