YAML CONFIGURATION, LOCALLY
Convert one YAML document to JSON.
Convert a single YAML 1.2 document with ordinary scalars, lists, and mappings into formatted JSON in your browser.
Paste one YAML document, then convert it to formatted JSON.
Supported YAML subset
This converter uses the YAML 1.2 Core schema for one document containing ordinary scalars, lists, and mappings. It rejects duplicate keys, multiple documents, unsupported values, cyclic aliases, non-finite numbers, and inputs over 100,000 characters. Results are JSON with two-space indentation; YAML comments and formatting are not carried into JSON. This is a format conversion helper, not a validator for an application's configuration rules. Page content updated November 3, 2026.
The parser is the local yaml JavaScript library (version 2.9.1, ISC license), bundled with this site; no parser request is made to a server.
Runs in your browser. No uploads. No account.
Good to know
Which YAML version and features are supported?
Parsing uses the YAML 1.2 Core schema for a single document with ordinary scalar, sequence, and mapping values. Application-specific YAML tags and YAML 1.1-only behavior are outside this tool's stated subset.
What happens with duplicate keys or multiple documents?
Duplicate mapping keys are reported as an error, and the converter accepts one document per conversion. Split a multi-document stream before using the tool.
Are comments and formatting preserved?
No. The converter turns YAML data into JSON values, so comments, blank lines, and original formatting are omitted.
Does my YAML leave this browser?
No. The parser and conversion run locally in this tab; your input is not uploaded or saved by the tool.
Is it free?
Yes, during beta. Optional usage-credit plans are coming soon. Payments are not available and no credits are required.
Sources and method
Method checked November 3, 2026. The YAML specification defines the language and its data model. Parser implementation: yaml JavaScript library 2.9.1 under the ISC license; the local license text is included with the bundled parser.
How it works
1. Paste one YAML 1.2 document. 2. Convert it locally using the Core schema. 3. Review or copy the formatted JSON; duplicate keys and multiple documents are reported.
Good to know
Which YAML features are supported?
One YAML 1.2 document with ordinary scalar, sequence, and mapping values uses the Core schema.
Does the tool preserve comments or formatting?
No. YAML comments and formatting do not have a direct representation in JSON and are omitted.
Does my configuration leave this browser?
No. Parsing and conversion run in this browser tab; your input is not uploaded or saved.
Is it free?
Yes, during beta. Optional usage-credit plans are coming soon. Payments are not available and no credits are required.