YAML vs JSON vs XML

A Quick Guide and Cheatsheet for Programmatically Storing Data

Overview

Data within these formats share several common traits:

• Structured for Code
• Annotated for Humans
• Open Source
• Platform Agnostic
• Describes its own data

Feature Comparison

Feature	YAML	JSON	XML
Readability	Very readable	Readable	Less readable; verbose syntax
Data Types	Strings, numbers, lists, associative arrays	Objects, arrays, strings, numbers, booleans, null	Wide range via schemas
Comments	Supported	Not supported	Supported
Hierarchy	Indentation	Braces and brackets	Tags and attributes
Extension	.yaml or .yml	.json	.xml
Metadata	Limited via tags	No direct support	Extensive via attributes/namespaces
Parsing	Requires libraries	Native in most languages	Requires libraries
Common Use Cases	Config files, simple data	Web APIs, data exchange	Complex structures, legacy systems
Error Tolerance	More tolerant, flexible	Less tolerant, strict syntax	Less tolerant, strict syntax

XML

• Legacy Support: XML (eXtensible Markup Language) is often used in older systems and SOAP (Simple Object Access Protocol) APIs.
• Verbose Syntax: XML can be less readable due to its extensive use of tags and attributes.
• Strong Metadata Support: XML allows for complex data structures with extensive support for attributes and namespaces.

JSON

• Popular: JSON (JavaScript Object Notation) is widely used, especially in web development.
• Lightweight: JSON is compact and easy to parse, making it ideal for data interchange between servers and web applications.
• Native to JavaScript: JSON is the default format for data in JavaScript environments.

YAML

• Highly Readable: YAML (YAML Ain’t Markup Language) is designed to be human-readable, using indentation to define structure.
• Compact: YAML files are often smaller and more straightforward than their JSON or XML counterparts, making them ideal for configuration files.
• Flexible: YAML’s syntax allows for easy editing and error tolerance, making it a favorite for DevOps and configuration management.