YAML Formatter instantly cleans up and standardizes YAML indentation, spacing, and structure. YAML is extremely indentation-sensitive — a single misaligned space can break a Kubernetes deployment, Docker Compose service, or GitHub Actions workflow. Paste your YAML and get a correctly indented, human-readable output in seconds, verified against YAML 1.2 spec rules.
YAML formatting normalizes indentation using consistent spacing and removes redundant whitespace while preserving the document structure. The tool respects YAML 1.2 spec conventions including block mappings, sequences, folded scalars, and multi-document files separated by ---.
YAML uses indentation (not braces or brackets) to define data hierarchy. A misaligned space causes a parse error: "mapping values are not allowed here" or "expected block end" — making the entire config file invalid.
Always spaces. The YAML spec prohibits tab characters for indentation. This formatter ensures tabs are converted to spaces (2 spaces per level by default).
Yes. The formatter parses YAML before formatting — if the input is invalid YAML (syntax error), an error message is shown rather than returning malformed output.
No. Everything runs in your browser. Your config files are never uploaded.
Yes. YAML files with multiple documents separated by --- are supported.
Yes, completely free. No account required.
Tool workspace
Free YAML formatter online — instantly fix YAML indentation, beautify config files, and validate structure. Perfect for Kubernetes YAML, Docker Compose, and GitHub Actions workflows.
Output
Input
name: John address: city: London zip: EC1A
Output
name: John address: city: London zip: EC1A
