About

This tool facilitates the transformation of JSON (JavaScript Object Notation) strings into YAML (YAML Ain't Markup Language) format. While JSON is ubiquitous in API responses and web data transfer due to its strict structure and parsing efficiency, YAML is often preferred for configuration files (such as Docker Compose, Kubernetes manifests, and CI/CD pipelines) because of its readability and support for comments. The converter parses your JSON input, validates the syntax, and recursively reconstructs the data hierarchy using YAML indentation rules.

Formulas

The conversion process involves traversing the JSON Document Object Model (DOM) and mapping specific data structures to their YAML equivalents using indentation logic.

Parsing. The input string is validated and parsed into a native JavaScript object.
Mapping Objects. JSON Key-Value pairs {"key": "value"} are transformed into key: value strings. Nested objects trigger an indentation increment (typically 2 spaces).
Mapping Arrays. JSON Lists ["item1", "item2"] are converted to block sequences denoted by hyphens:
- item1
- item2.
Escaping. Strings containing special characters or matching YAML keywords (like 'true', 'null') are wrapped in quotes to ensure type safety.

This process ensures the output remains semantically identical to the input while adopting the visual structure of YAML.

Reference Data

Feature	JSON	YAML
Syntax Style	Braces `{}`, Brackets `[]`	Indentation (Spaces)
Comments	Not supported (officially)	Supported (`# comment`)
Readability	Lower (dense, structural chars)	High (clean, visual hierarchy)
Data Types	Strings, Numbers, Booleans, Null, Arrays, Objects	Extends JSON types + Timestamp, Binary, etc.
Root Node	Must be Object or Array	Can be any valid node

Frequently Asked Questions

No. Standard JSON does not support comments. If your input is 'JSON5' or loose JSON with comments, the standard parser will likely throw an error, and even if parsed, comments are not part of the data structure and thus disappear in the YAML output.

In JSON, a null value is represented explicitly as `null`. In the YAML output generated by this tool, it is typically represented as `null` or a tilde `~` depending on the strictness, though this tool defaults to `null` for clarity.

Unlike JSON, which relies on braces and brackets for structure, YAML relies entirely on indentation (whitespace) to define hierarchy. A mismatch in indentation levels changes the relationship between data points, potentially breaking configuration files.

The conversion happens client-side in your browser. While modern browsers are efficient, attempting to parse and render multi-megabyte JSON strings (e.g., >50MB) may cause UI freezing or memory warnings depending on your device's capabilities.