Data & Codecs

YAML & XML Validator and Converter

Validate, format, and convert YAML, XML, and JSON locally using safe schemas, bounded alias expansion, strict XML DTD/entity blocking, and line/column syntax errors.

Zero fetches, no custom YAML tags, XML DTD/DOCTYPE & external entities blocked · Max 1024 KB · Depth 128 · Max 25 YAML aliases.

Input FormatTarget OutputYAML SchemaIndentation

Source (YAML)

Converted Output (JSON)

{
  "defaults": {
    "timeout": 30
  },
  "service": {
    "timeout": 30,
    "released_at": "2026-11-11T12:00:00Z",
    "tags": [
      "web",
      "api"
    ]
  }
}

Documented Mapping & Safety Notes

Resolved 1 YAML alias reference(s) within safe limit (25).
Preserved 1 ISO date/timestamp scalar(s) as exact strings under safe YAML 1.2 core schema (no Date object coercion).

XML → JSON & YAML Safe Mapping Reference

XML attributes map to "@attributes", namespace prefixes stay on tag keys (e.g. "ns:book"), mixed text becomes "#text", and repeated sibling tags become arrays [...]. YAML parses via YAML 1.2 core/json schemas with custom tags blocked and aliases capped at 25.