Docker Compose Validator
Validate docker-compose.yml: syntax, services, ports, volumes, networks.
3 services2 errors1 warningFix the errors above
WARN · Obsolete version key: The "version" key is obsolete — Compose v2 ignores it. Remove it.
ERROR · Unknown network: Service "web" references network "appnet" which is not listed under top-level networks.
ERROR · Duplicate host port: Host port 8080 is bound by both "web" and "api" — the second binding fails at startup.
INFO · Default network: No top-level networks section — services share the implicit "default" network.
Validates YAML syntax, service definitions, port bindings, and references to networks/volumes/depends_on against the Compose spec. $VARIABLE interpolation, .env files, and external resources are not resolved here. Parsing runs entirely in your browser.
//Share this tool
//Related tools
JSON Formatter
Format, validate, minify, and prettify JSON data instantly.
JWT Decoder
Decode and inspect JWT tokens: header, payload, signature, expiration.
Base64 Encoder/Decoder
Encode text or files to Base64 and decode back. UTF-8 safe.
Regex Tester
Test regular expressions in real-time with match highlighting and groups.
Validate docker-compose.yml files for syntax and structure: service definitions, port conflicts, and dangling references to networks, volumes, and depends_on services. Catch "services must be a mapping, not a string" before your stack fails to start.
[x]Features
- -Strict YAML parsing with line-level error messages
- -Service name and image/build checks
- -Duplicate host port detection across services
- -Unknown network, volume, and depends_on references
- -Obsolete version key warning
- -Local-only processing with sample compose file
>Use Cases
- >Debugging compose files that fail to start
- >Checking for port collisions in monorepo stacks
- >Reviewing shared compose templates
- >Teaching compose indentation and structure