YAML is the format people write; JSON is the format tools consume. Converting lets you feed a manifest to an API that only accepts JSON, inspect exactly how a YAML parser understood your indentation, or debug a value that YAML quietly typed as a number or boolean.
What you'll learn
- Convert YAML to indented JSON as you type
- Spot YAML type surprises such as 1.10 becoming 1.1 or a port becoming a number
- Convert multi-document files (--- separated) in one go
Step by step
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Paste the YAML
Open YAML to JSON and paste the document. The conversion runs on every keystroke, so you can fix indentation errors live.
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Read the JSON output
Mappings become objects and sequences become arrays. Scalars keep the type the YAML parser inferred, which is the most common source of surprises.
name: Ada roles: - admin - user → { "name": "Ada", "roles": ["admin", "user"] } -
Check inferred types
Unquoted 8080 becomes a number and 1.10 becomes 1.1. This converter follows YAML 1.2, so yes, no, on and off stay strings, but older YAML 1.1 parsers such as PyYAML turn them into booleans. Quote anything that must stay a string.
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Copy the result
Use Copy Output. A file with several --- separated documents comes out as a JSON array with one element per document.
Common problems
bad indentation of a mapping entry
A line is indented by a different number of spaces than its siblings, or a tab crept in. YAML requires spaces and consistent indentation within a block.
A port or version came out as a number
YAML types 8080 as a number and 1.10 as 1.1. Quote them ("8080", "1.10") if the consuming system expects strings.
yes and no became true and false somewhere else
That system uses a YAML 1.1 parser. This converter keeps them as strings, so quote yes, no, on and off in the source file to get the same result everywhere.
FAQ
Does it support anchors and aliases?
Yes. Anchors (&) and aliases (*) are resolved, so the JSON contains the expanded values.
Can I convert JSON back to YAML?
Yes, with the JSON to YAML converter, linked below.