Docker & Containers
Review one Compose YAML document, its declared connections and unresolved references.
The YAML stays in this browser. No Docker, environment-file or network request is made.
The source is visible. Revealing output enables YAML export with its original values, including secrets.
Static check: Compose schema fee041b (2026-09-01). No interpolation, file loading, profile activation or container execution.
Up to 200,000 UTF-16 units, 100 services and 500 relation records. Views show 50 records at a time.
Input or options changed. Analyze again before exporting.
Use the Docker Compose editor before reviewing a stack change: a valid YAML file can still contain two services bound to the same host port or a volume name that nobody declared. Keep the original text beside a formatted result, then follow each diagnostic back to its source. The report describes declarations, not running containers.
The Docker Compose editor puts service dependencies, volume mounts and published ports beside the YAML. An arrow runs from the dependent service to its dependency; it does not imply that a database is healthy. Explicit namespace and link relationships also appear, so an indirect connection is not hidden in a long service block.
A fixed host binding can collide even when its container target differs. TCP and UDP are checked separately. Overlapping allocation ranges, mixed IPv4/IPv6 wildcards and profiled services receive a potential-overlap warning, because the final allocation or active service set is unknown.
Syntax errors include a source line and column. Schema findings identify the offending field; fix these before relying on the semantic views. The official schema is bundled at a fixed revision, so a version field does not select an older validation mode.
The port view separates host and container sides. Two containers can both listen on port 80. A collision concerns the host address, published port and protocol. Variables and automatic assignments remain unresolved rather than becoming invented numbers.
The source editor remains visible, but the full output is hidden initially. Enable Show configuration values before copying or downloading YAML. ENV export always contains empty values. Turn automatic analysis off to use Analyze or Ctrl/Cmd + Enter; changing input immediately disables old exports.
This Docker Compose validator uses the official 2026-09-01 schema snapshot plus focused checks for absent services, undeclared resources, dependency cycles and invalid port syntax. Unknown fields are reported rather than silently removed. Formatting does not sort keys or rewrite the input.
Inspect depends_on in short or long form, its condition, service namespace links and volume sources. Named volumes are checked against top-level declarations. Bind paths are displayed without opening them, and anonymous volumes remain distinct from named resources.
The compose file checker scans string values for $VAR and braced expressions, including nested alternatives. Double dollars escape interpolation. Bare environment entries and null map values are recorded as shell passthrough. The template sorts unique names and emits NAME=, never a guessed secret.
A YAML download keeps actual values, comments, anchors and interpolation text. The JSON report omits the full YAML and variable defaults but retains diagnostic paths and relations. Views reveal 50 records at a time; exports contain all records within the documented limits.
No. It parses the document and checks its structure and selected relationships in a browser worker. It cannot inspect a Docker daemon or tell whether an image, volume, secret or network really exists on your host.
The pinned schema covers its documented structure, while the additional semantic rules have a narrower scope. Environment interpolation, external files, runtime health and deployment behavior remain outside the analysis. Warnings identify some unresolved cases; passing does not replace a real configuration check.
It checks against the modern Compose Specification snapshot, not the historical versioned schemas. A version key is retained and receives a compatibility warning. An older file can pass if its fields match this schema, but the version number does not switch engines.
Not directly. The input is one YAML document. include and extends are reported as unsupported context rather than fetched or merged. Resolve the project with your local Compose tooling first, then review the resulting single-file configuration here.
The checker does not know which profiles you will activate. It considers every declared service and downgrades overlaps involving profiled services to potential conflicts. Confirm the active set and allocated host ports in the environment where you will start the stack.
Found a Compose declaration that needs a clearer diagnosis?
Return to the Docker Compose editor, resolve the diagnostic paths, and export the configuration only after checking its host bindings and external dependencies.