Developer ToolsCode ValidatorsFree Tool
YAML Validator
Run basic heuristic checks on YAML — flags tab characters (invalid in YAML) and possible key/value formatting issues.
How to Use YAML Validator
- 1Paste your YAML content
- 2Click Process
- 3Review any flagged tab or formatting issues
Frequently Asked Questions
Two things per line: whether it contains a tab character (YAML disallows tabs for indentation) and whether a line ending in a colon might have a key/value formatting issue. It also reports the total line count.
No — it's a lightweight heuristic pass, not a real YAML parser. It won't catch all invalid YAML (like incorrect anchors, bad flow-style syntax, or type errors) and may occasionally flag valid YAML.
The YAML spec reserves tab characters and doesn't allow them for indentation — this is one of the few checks this tool can reliably catch with a simple pattern match.
No — all checks run in your browser; nothing is uploaded.
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