YAML Validator – Indentation & Syntax Error Checker
Validate YAML syntax locally in your browser. Spot indentation errors, duplicate keys, unresolved anchors/aliases, line and column numbers, and format clean YAML code.
YAML Validator Features
Indentation level checking, duplicate key detection, and anchor validation
📐 Indentation Level Checker
Detects space vs tab indentation mismatches and key alignment errors.
⚠️ Duplicate Key Detection
Flags duplicate mapping keys within the same nesting block that silently overwrite values.
⚓ Anchor & Alias Verification
Verifies declared anchors (`&anchor`) and matching aliases (`*alias`) across configuration documents.
🔒 100% Client-Side Privacy
Validation runs in local browser RAM. Zero YAML configuration files are uploaded to servers.
How to Use YAML Validator
Input YAML Document
Paste YAML configuration text, drag & drop a .yaml file, or click Load Sample YAML.
Inspect Validation Output
Review the green success badge or red syntax error callout detailing indentation or key issues.
Copy or Download YAML
Click Copy or Download to save clean YAML configuration files.
Frequently Asked Questions
How does the YAML Validator detect indentation errors?
The YAML Validator parses indentation spacing, key-value colon alignment, and sequence dash levels, pinpointing exact line numbers whenever tab vs space or level mismatches occur.
Is my YAML configuration safe during validation?
Yes, 100%. All YAML syntax checking, anchor/alias resolution, and file downloads run locally inside your browser's RAM memory using client-side JavaScript. Zero data is sent to external servers.
Does the tool support YAML anchors and aliases?
Yes! The validator verifies that all declared anchors (&anchor) have matching, valid aliases (*alias) throughout your configuration document.