YAML to JSON Converter

How to Convert YAML to JSON

1. Paste YAML: Enter or paste your YAML content into the left editor. The tool validates syntax automatically.
2. Convert to JSON: Click "YAML to JSON" to convert. The formatted JSON appears in the right editor.
3. Convert back: Paste JSON into either editor and click "JSON to YAML" to convert to YAML format.
4. Swap content: Click "Swap" to exchange the content between YAML and JSON editors.
5. Copy results: Use the "Copy" buttons to copy YAML or JSON output to your clipboard.

What is YAML?

YAML (YAML Ain't Markup Language) is a human-friendly data serialization format commonly used for configuration files and data exchange. It uses indentation and simple syntax to represent data structures, making it more readable than JSON or XML. YAML is widely used in DevOps tools (Docker Compose, Kubernetes, Ansible), CI/CD pipelines (GitHub Actions, GitLab CI), and application configuration.

YAML supports the same data types as JSON (objects, arrays, strings, numbers, booleans, null) but with a cleaner, more readable syntax. It uses indentation instead of brackets, colons for key-value pairs, and hyphens for arrays. Comments are supported with the # symbol, making YAML ideal for human-edited configuration files.

YAML vs JSON Comparison

Readability: YAML is more human-readable with minimal punctuation. JSON uses brackets and braces which can clutter complex structures.

Comments: YAML supports comments (#), JSON does not. Comments are crucial for documenting configuration.

Strict syntax: JSON requires quotes around strings and doesn't allow trailing commas. YAML is more lenient.

Data types: Both support the same basic types, but YAML has additional features like anchors and references.

File size: YAML is often more compact due to less punctuation, though JSON can be minified more aggressively.

Parsing speed: JSON parses faster. YAML parsers are more complex due to flexible syntax.

Common Use Cases

Configuration Files: Convert between formats when migrating between tools or languages that prefer different formats.

API Development: Convert API responses between YAML (for documentation) and JSON (for actual responses).

DevOps & CI/CD: Convert Docker Compose, Kubernetes manifests, or CI pipeline configurations between formats.

Data Migration: Transfer data between systems that use different serialization formats.

Testing: Convert test fixtures or mock data between formats for different testing frameworks.

Documentation: Convert configuration examples between YAML (human-friendly docs) and JSON (API specs).

YAML Syntax Basics

Key-value pairs: key: value - Colons separate keys from values, space after colon is required.

Lists/Arrays: Use hyphens: - item1 - item2 or inline: [item1, item2]

Objects/Maps: Indented key-value pairs or inline: {name: John, age: 30}

Strings: Can be unquoted, single-quoted, or double-quoted. Quotes needed for special characters.

Multi-line strings: Use | for literal block or > for folded block.

Comments: Start with #, continue to end of line.

JSON Syntax Basics

Objects: {"key": "value"} - Keys must be strings in double quotes.

Arrays: ["item1", "item2"] - Square brackets, comma-separated values.

Strings: Must use double quotes. Single quotes are invalid.

Numbers: Integers or decimals, no quotes: 42, 3.14

Booleans: true or false (lowercase only).

Null: null represents empty values.

Common Conversion Pitfalls

Indentation in YAML: YAML uses spaces for indentation, never tabs. Inconsistent indentation causes parsing errors.

Quoted strings: In YAML, unquoted strings starting with special characters need quotes: "@special"

Boolean values: YAML recognizes yes/no, on/off, true/false as booleans. In JSON, only true/false work.

Numbers as strings: YAML may interpret 3.10 as a number, losing trailing zero. Quote it as "3.10" to preserve as string.

Special characters: Characters like :, -, ?, # have special meaning in YAML and may need quoting.

Best Practices

Use YAML for configuration files that humans will edit regularly - its readability and comment support make it ideal for this purpose. Use JSON for data interchange between systems, APIs, and wherever parsing speed matters. When converting between formats, validate the output to ensure data integrity, especially for complex nested structures. Consider using schema validation (JSON Schema, YAML Schema) to catch errors before deployment.

Related Tools

Need to convert JSON back to YAML? Use the JSON to YAML Converter. Also format JSON output with the JSON Formatter or convert to CSV with the JSON to CSV Converter.