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Syntax Validation & Diagnostics

YAML Validator

Validate YAML syntax, detect indentation errors, inspect document structure, and resolve parsing issues locally in your browser.

  • Processed locally
  • No upload required
  • No account required
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YAML Document Editor401 bytes • 22 lines

Valid YAML Document

Your YAML syntax is well-formed according to the official YAML specification.

Document Statistics

Total Lines

22

Byte Size

401 B

Root Type

object

Top-Level Keys

3

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About YAML Validator – Check & Validate YAML Syntax Online

Validate YAML configuration files, Kubernetes manifests, and GitHub Actions workflows with precision.

Detect syntax errors, tab violations, and inconsistent indentation without altering your source code.

Input is processed locally in your browser and is not sent to Navorika.

How the calculation works

CST / AST Verification

A concrete syntax tree parser evaluates indentation blocks, key-value mappings, multiline literals, and scalar tokens.

Structural Diagnostics

When an error is detected, the validator calculates the exact line number, column offset, and context snippet.

How to use this tool

  1. 1Paste or upload your YAML content in the editor.
  2. 2Click Validate YAML or use live validation to view real-time diagnostics.
  3. 3If an error occurs, inspect the highlighted line, column, and snippet pointer.
  4. 4Copy or download your validated YAML once all syntax errors are resolved.

Understanding the result

A green status banner indicates valid YAML syntax according to the specification.

A red alert banner indicates syntax violations such as bad indentation, tab characters, or unquoted reserved characters.

Important limitations

  • The validator verifies syntax and structural well-formedness, not custom domain schemas (such as specific Kubernetes CRDs).
  • Custom application-specific tags (!tag) must follow standard YAML tagging syntax.

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Frequently asked questions

Why does YAML reject tab characters?

The YAML specification strictly forbids literal tab characters for indentation because different editors display tabs with varying column widths.

Does this tool change my YAML formatting?

No. The validator only parses and checks your input; it never rewrites, reformats, or alters your text.

Can I test broken YAML to see error reporting?

Yes. Click the Sample Broken button to observe how line and column diagnostics are reported.

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