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Convert YAML to JSON Online Convert YAML to formatted JSON with configurable indentation.

YAML to JSON illustration
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YAML to JSON

Convert YAML to formatted JSON with configurable indentation.

1

Paste YAML

Paste your YAML content into the input field.

2

Choose indentation

Select 2 or 4 spaces for JSON formatting.

3

Copy JSON

Copy the formatted JSON output for your application.

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What Is YAML to JSON?

YAML to JSON converts YAML Ain't Markup Language into JavaScript Object Notation format. YAML is often used for configuration files due to its human-friendly syntax, but many applications, APIs, and tools require JSON. This converter uses the js-yaml library to accurately parse your input — including advanced features like anchors, aliases, multi-line strings, and complex types — and outputs clean, formatted JSON. You can choose between 2-space and 4-space indentation for the output.

Why Use YAML to JSON?

  • Accurate YAML parsing supporting anchors, aliases, and all YAML features.
  • Configurable JSON indentation (2 or 4 spaces).
  • Handles complex YAML types including multi-line strings and nested structures.
  • Instant real-time conversion with error reporting for invalid YAML.

Common Use Cases

API Development

Convert YAML configuration into JSON for API payload testing and integration.

Configuration Migration

Transform YAML config files to JSON for applications that require JSON configuration.

Data Processing

Convert YAML data files to JSON for processing with JavaScript applications.

Documentation

Convert YAML examples to JSON for API documentation and tutorials.

Technical Guide

The converter uses js-yaml's load() function with default safe schema to parse YAML input. This schema supports all standard YAML 1.2 types including strings, integers, floats, booleans, null, sequences (arrays), and mappings (objects).

Advanced YAML features are fully supported: anchors (&anchor) and aliases (*anchor) are resolved to their referenced values, multi-line strings (| and > block scalars) are properly converted, and merge keys (<<) are expanded.

The parsed YAML object is then serialized to JSON using JSON.stringify() with configurable indentation. The indentation options (2 or 4 spaces) allow you to match your project's code style.

Error handling: invalid YAML produces a descriptive error message from js-yaml's parser, including the line number and character position of the error.

Tips & Best Practices

  • 1
    YAML comments are ignored during conversion — JSON does not support comments.
  • 2
    YAML anchors and aliases are resolved to their actual values in the JSON output.
  • 3
    Multi-line YAML strings (using | or >) are converted to JSON strings with \n escape sequences.
  • 4
    Use 2-space indentation for compact JSON, 4-space for more readable output.

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Frequently Asked Questions

Q Are YAML comments preserved?
No, JSON does not support comments. YAML comments are discarded during conversion.
Q How are YAML anchors handled?
Anchors and aliases are resolved to their referenced values in the JSON output.
Q What about multi-line strings?
YAML block scalars (| and >) are converted to JSON strings with \n newline characters.
Q What YAML version is supported?
js-yaml supports YAML 1.2 specification with common 1.1 compatibility.
Q Can I minify the JSON output?
Not directly, but you can use our JSON Minifier tool on the output.

About This Tool

YAML to JSON is a free online tool by FreeToolkit.ai. All processing happens directly in your browser — your data never leaves your device. No registration or installation required.