YAML Syntax Checker

Before validating schema, YAML must parse. The YAML Syntax Checker scans your text for the formatting mistakes that break parsers: tabs instead of spaces, inconsistent indentation, trailing whitespace, and missing colons.

Paste any YAML and get a line-by-line report of errors and warnings. Everything runs locally and nothing is uploaded.

• Tabs vs spaces - flags tab indentation.
• Indentation - detects odd/multiple-of-2 issues.
• Missing colons - key lines without : .
• Trailing spaces - style warnings.
• Parse failures - structural errors with line numbers.
• Copy / Download / Print - take the report anywhere.

1. Paste YAML into the textarea.
2. Click check.
3. Read errors/warnings.

Example 1 - tab. a tab-indented line raises an error.

Example 2 - missing colon. key line without : raises an error.

• Fast catch - find formatting bugs early.
• Private - runs in the browser.
• Clear report - line-numbered issues.
• Copy, download or print - keep the report.