inyourbrowser.com

YAML Validator

Paste any YAML document and the validator reports whether the syntax is well-formed. Errors include the line and column where the parser stopped, making it easy to locate the problem.

Input YAML
Output

ACTION

INDENT

Runs entirely in your browser

How it works

The tool uses js-yaml, a YAML 1.2 parser written in pure JavaScript. The library loads lazily when you trigger an action, parses the input into an in-memory tree, and re-emits it using the chosen indentation. Validation surfaces any parser error along with the line where it occurred.

Processing runs in your browser

All parsing and conversion happens locally in your browser tab. Our servers are not involved at any point.

Frequently asked questions

Is my YAML sent to a server during validation?
All validation happens in your browser using the js-yaml parser. Our servers are not involved at any point.
What kind of errors does the validator catch?
Indentation mismatches, duplicate keys, unterminated strings, invalid escape sequences, and any structural issue that prevents the document from parsing.
Does the validator check semantic rules like Kubernetes schemas?
The validator confirms YAML syntax only. Schema-level rules for Kubernetes, OpenAPI, or other formats require a separate schema validator.
Why does the validator say my file is invalid when it looks fine?
Common causes include mixed tabs and spaces, trailing colons without values, or a Byte Order Mark at the file start. The error message includes the line number to help locate the issue.

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