What YAML errors does this catch?

Indentation inconsistencies, invalid characters, duplicate keys, incorrectly typed values, tab characters where spaces are required, and structural issues like unclosed mappings or sequences.

Can it validate Kubernetes or Docker Compose YAML?

It validates YAML syntax. For schema validation (e.g., checking that a Kubernetes manifest has required fields), use a dedicated Kubernetes linter like kubeval.

Is there a file size limit?

There is no server-side limit since all processing runs in your browser. Very large YAML files may take a moment depending on your device.

Best Free Online YAML Validator

A single indentation error or incorrect data type in a YAML file can crash a deployment or break a CI workflow with a cryptic error message. devtoolkit.sh's YAML Validator checks any YAML document against the full YAML 1.2 specification and reports the exact line and column of every syntax error, making it fast to locate and fix problems. It also reports the document structure — top-level keys, nesting depth, and detected value types — to give you a quick overview of a YAML file you did not write. All validation runs locally in your browser without uploading your files anywhere.

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FAQ

What YAML errors does this catch?: Indentation inconsistencies, invalid characters, duplicate keys, incorrectly typed values, tab characters where spaces are required, and structural issues like unclosed mappings or sequences.
Can it validate Kubernetes or Docker Compose YAML?: It validates YAML syntax. For schema validation (e.g., checking that a Kubernetes manifest has required fields), use a dedicated Kubernetes linter like kubeval.
Is there a file size limit?: There is no server-side limit since all processing runs in your browser. Very large YAML files may take a moment depending on your device.