How do I validate YAML?

Paste your text above. If parsing succeeds, you see Valid YAML; otherwise you see the error details.

Why is my YAML invalid?

Common causes include inconsistent indentation, tabs mixed with spaces, and misaligned list items under a key.

What are common YAML indentation errors?

Children must indent further than their parent, siblings must align, and list dashes must line up consistently.

Can I validate YAML online?

Yes. This free validator works in your browser with no account and no install.

How do I check YAML syntax?

Paste the document here to parse it. Pair the result with a quick visual scan of indentation for nested maps and lists.

What is YAML Validator?

A free online tool that checks whether text is valid YAML for students and developers.

How does the YAML Validator work?

It parses your text with a YAML library in the browser and maps failures to line and column hints when available.

How do I use the YAML Validator?

Paste YAML, optionally load a valid or broken example, and read the status panel.

Is this YAML Validator free to use?

Yes. It is free with no sign-up.

Can I use the YAML Validator on mobile?

Yes. Mobile browsers are supported.

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Developer

YAML Validator

Validate YAML instantly in your browser. Catch indentation mistakes and syntax errors before they break CI pipelines.

Runs in your browser — your data stays on your device

Free tool

YAML looks simple until a single space breaks a deploy. This free YAML validator checks syntax locally so developers, DevOps beginners, and students can validate automation configs, Linux manifests, and CI/CD files during coding practice—without installing software. Paste the document, fix the reported line, and re-check.

How to use the YAML Validator

1
Paste the YAML you want to check.
2
Read Valid YAML or the parser error with an approximate line and column.
3
Fix the indentation or syntax issue, then re-paste to confirm.

Why YAML validation saves CI minutes

Tabs mixed with spaces, misaligned list items, and accidental duplicate keys are the top classroom failures. Catching them here before you push keeps pipelines focused on real test failures—not punctuation.

YAML validator with examples

Tap Valid example to see a clean course config, then Broken example to watch indentation errors surface with a line hint.

Guides and next steps

Privacy note

YAML validation runs entirely in your browser. We do not upload your documents.

Frequently asked questions

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