YAML to JSON Converter

About This Tool

YAML and JSON are the two most popular formats for configuration files, API payloads, and data serialization. Kubernetes manifests, Docker Compose files, GitHub Actions workflows, and Ansible playbooks all use YAML. REST APIs, package managers, and databases prefer JSON. Developers frequently need to convert between the two when migrating configurations, preparing API payloads, or debugging YAML syntax errors by inspecting the equivalent JSON structure. This bidirectional converter handles both directions: paste YAML on the left and get JSON on the right, or paste JSON on the right and get YAML on the left. It supports nested objects, lists, booleans, numbers, null values, inline arrays, and comments. The converter processes all data on your device with no external dependencies or server calls.

YAML vs JSON: Key Differences

Both formats represent the same data structures but with different syntax philosophies:

• Readability: YAML uses indentation and minimal punctuation, making it more readable for configuration files. JSON uses braces and brackets, which makes it easier for machines to parse.
• Comments: YAML supports comments with #. JSON has no comment syntax, which is one of the most common complaints from developers.
• Data types: Both support strings, numbers, booleans, null, arrays, and objects. YAML also supports multi-line strings and anchors/aliases for reuse.
• File size: YAML files are typically smaller because they avoid curly braces, square brackets, and quotes around keys.
• Parsing: JSON is faster to parse because its grammar is simpler and unambiguous. YAML parsing is more complex due to indentation sensitivity.

How the Conversion Works

When converting YAML to JSON, the parser processes each line and builds a data structure based on indentation levels:

• Key-value pairs: name: John becomes {"name": "John"}
• Nested objects: Indented keys under a parent key become nested objects
• Lists: Lines starting with - become JSON arrays
• Type inference: true/false become booleans, numbers are parsed automatically, null and ~ become null
• Inline syntax: [a, b, c] and {key: value} are supported for compact notation

The JSON to YAML direction reverses this process, converting braces and brackets into indentation-based hierarchies.

Common Conversion Scenarios

Developers convert between YAML and JSON in these situations:

• Kubernetes debugging: Convert a YAML manifest to JSON to use with kubectl or API calls that require JSON input
• CI/CD pipelines: Many tools accept both formats but their documentation may only show one. Convert to match your preferred style.
• API testing: Convert YAML config files to JSON for use in tools like Postman or curl
• Documentation: Convert JSON API response examples to YAML for cleaner documentation formatting
• Migration: Move configuration from one tool (JSON-based) to another (YAML-based) or vice versa

Supported YAML Features

This converter handles the most common YAML constructs used in real-world configuration files:

• Scalar types: Strings, integers, floats, booleans (true/false), and null (null or ~)
• Quoted strings: Both single and double-quoted strings preserve their content as-is
• Nested mappings: Objects within objects, indented with two spaces per level
• Sequences: List items prefixed with -
• Comments: Lines starting with # are ignored during parsing
• Inline collections: [a, b, c] for arrays and {key: val} for objects

Advanced features like anchors (&), aliases (*), multi-line strings (|, >), and custom tags are not supported by this simplified parser. For those features, use a full YAML library in your preferred programming language.

Frequently Asked Questions