YAML Parser Online — Parse YAML to JSON & Inspect Types

OpenFormatter's YAML parser converts your YAML to JSON and lists every key with its inferred data type. This is the fastest way to debug surprises like an unquoted yes being interpreted as a boolean, an IP address being trimmed of leading zeros, or a phone number losing its leading +. All parsing happens in your browser — no upload, no rate limit.

How to parse YAML online — 4 steps

1. Paste your YAML. Drop config, a manifest, or any .yaml content into the Input panel — or click Load Sample.
2. Click Parse. The parser runs client-side and produces both a JSON view and a key→type breakdown.
3. Inspect types. Read the type list to confirm each value parsed exactly as you expected — string, number, boolean, null, array, object.
4. Copy the JSON. Copy the JSON equivalent for use in tests, code, or downstream tooling.

Sample YAML and parse output

For an input like this:

port: 8080
debug: false
allowed_hosts:
  - api.example.com
  - admin.example.com
database:
  host: db.internal
  ssl: true

The parser produces a type breakdown:

port → number (8080)
debug → boolean (false)
allowed_hosts → array (2 items)
database → object
database.host → string ("db.internal")
database.ssl → boolean (true)

…and the JSON equivalent your tooling will see:

{
  "port": 8080,
  "debug": false,
  "allowed_hosts": ["api.example.com", "admin.example.com"],
  "database": { "host": "db.internal", "ssl": true }
}

Common YAML parsing surprises

• check_circleThe Norway problem — unquoted "no" becomes false in YAML 1.1
• check_circleA phone number 0123456 may parse as octal in YAML 1.1
• check_circleA version string 2.0 parses as a float — quote it ("2.0") to keep it a string
• check_circleAn empty value (key:) becomes null, not an empty string
• check_circleA YAML date 2024-01-15 may be parsed as a Date object, not a string, in some libraries
• check_circleMulti-line strings using > collapse newlines to spaces; | preserves them
• check_circleAnchors and aliases are resolved at parse time — the alias name disappears
• check_circleDuplicate keys at the same level silently overwrite — most parsers take the last one

YAML parser vs validator vs viewer

Three related tools, three different jobs:

• Validator — checks the YAML is syntactically correct. Output: pass / fail.
• Viewer — renders the YAML as a clean indented tree. Output: pretty YAML.
• Parser — produces the actual parsed data structure with types. Output: JSON + type map.

Reach for the parser when validation passes but your application behaves unexpectedly — almost always because of a type-inference quirk.