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YAML ↔ JSON Converter

Convert YAML to JSON and JSON to YAML without losing structure.

This local two-way page composes IT Tools' separate YAML → JSON and JSON → YAML tools.

Runs locally in your browser. Your input is not uploaded or stored. You can verify this in your browser’s network panel.

What does this tool solve?

YAML is a human-friendly superset of JSON. Convert YAML configs to strict JSON, or JSON data to readable YAML — parsed with a real YAML parser, so errors point at actual syntax problems.

What examples should you start with?

YAML to JSON

Input

server:
  port: 8080
  hosts:
    - a
    - b

Output

{
  "server": {
    "port": 8080,
    "hosts": [
      "a",
      "b"
    ]
  }
}

JSON to YAML

Input

{"debug":true,"tags":["x","y"]}

Output

debug: true
tags:
  - x
  - y

How does it work?

Conversion parses the input into a data tree and re-serializes it in the target format. YAML anchors and references are resolved during parsing.

Type coercion follows YAML 1.2 rules — yes/no stay strings in JSON output of this parser, while true/false and numbers become JSON booleans and numbers.

What are the edge cases and limits?

  • Multi-document YAML (--- separators) is rejected; convert one document at a time.
  • Comments are a YAML-only feature and are lost when converting to JSON.
  • Key order is preserved as written, but JSON objects are unordered by spec — do not rely on ordering semantically.
  • YAML 1.1 booleans (yes/no/on/off) are parsed by js-yaml's JSON-compatible schema as strings in some cases — quote them in YAML if they must stay strings.

Technical reference

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