YAML to JSON Converter

How This Tool Converts YAML to JSON

• YAML key-value pairs become JSON object properties — each key: value line maps directly to "key": value in the JSON output.
• YAML sequences (lines prefixed with - ) become JSON arrays. Each list item becomes one array element, preserving order.
• YAML strings, integers, floats, booleans (true/false), and null are converted to their equivalent JSON types — the conversion is type-safe and lossless for standard YAML.
• YAML anchors (&name) and aliases (*name) are resolved during parsing. The output JSON contains the fully expanded values; anchor references are not preserved in the output.
• Indented YAML blocks become nested JSON objects, with each indentation level corresponding to one level of nesting in the JSON output.

When to Use YAML to JSON

• When an API, database, or tool only accepts JSON payloads but your source config is a YAML file (Kubernetes manifest, Docker Compose, Ansible playbook).
• When you want to inspect or query Kubernetes or Helm values with a JSON-aware tool like JSONPath Tester or jq.
• When a CI/CD pipeline outputs YAML and you need to extract specific values programmatically using a JSON parser.
• When migrating infrastructure-as-code from YAML-based tooling to a JSON-accepting pipeline or configuration system.

Worked example

A small config that shows how each YAML type maps to JSON — and one value that's easy to get wrong:

Input YAML

name: John Smith
port: 8080
enabled: true
country: NO
roles:
  - admin
  - editor

Output JSON

{
  "name": "John Smith",
  "port": 8080,
  "enabled": true,
  "country": "NO",
  "roles": [
    "admin",
    "editor"
  ]
}

What happened

• An unquoted string with spaces (John Smith) became a JSON string — YAML doesn't require quotes around most strings.
• port: 8080 became the number 8080 and enabled: true became the boolean true — YAML scalar types map straight to JSON types.
• The roles sequence became a JSON array, indentation replaced by brackets.
• country: NO stayed the string "NO" — because this tool's YAML 1.2 parser does not treat NO as a boolean. A YAML 1.1 parser would have turned it into false (see gotchas).

Edge cases & gotchas

• Parser version changes the result. This tool uses js-yaml 4 (YAML 1.2 core schema), so yes, no, on, off stay strings. Under YAML 1.1 — still used by many tools — those become booleans (the "Norway problem", where NO becomes false). Don't assume your downstream system parses the same way; quote values you need to stay strings.
• Anchors and aliases are expanded. A value defined with &anchor and reused via *alias is resolved to its full value in the JSON, so a value referenced three times appears as three copies — the reference itself is not preserved.
• Comments are dropped. YAML # comments carry no data and JSON has no comment syntax, so they disappear in the output.
• Only one document at a time. Multi-document YAML separated by --- isn't supported here — split it and convert each document separately.
• Very large integers can lose precision. A number beyond JavaScript's safe integer range (about 9 quadrillion) may be rounded, because the value passes through a JS number on the way to JSON.