JSON vs XML vs YAML: Complete Comparison
JSON is best for APIs (fast, lightweight, native to JavaScript), XML is best for enterprise (schemas, namespaces, transformations), and YAML is best for config files (readable, comments, minimal syntax). This guide compares JSON vs XML vs YAML syntax, performance, features, and when to use each format. Need to convert JSON to YAML? Try our free online converter.
JSON vs XML vs YAML: Quick Comparison
| Feature | JSON | XML | YAML |
|---|---|---|---|
| Syntax | Braces {}, brackets [] | Tags <tag></tag> | Indentation |
| Readability | Good | Moderate | ✅ Excellent |
| Comments | ❌ Not supported | ✅ <!-- comment --> | ✅ # comment |
| File Size | ✅ Smallest | Largest | Medium |
| Parse Speed | ✅ Fastest | Slowest | Medium |
| Schema Support | JSON Schema | ✅ XSD, DTD | Limited |
| Namespaces | ❌ No | ✅ Yes | ❌ No |
| Primary Use | APIs, web data | Enterprise, documents | Config files |
Syntax Comparison
The same data represented in all three formats:
JSON
{
"person": {
"name": "John Doe",
"age": 30,
"email": "[email protected]",
"hobbies": ["reading", "gaming", "hiking"]
}
}XML
<?xml version="1.0" encoding="UTF-8"?>
<person>
<name>John Doe</name>
<age>30</age>
<email>[email protected]</email>
<hobbies>
<hobby>reading</hobby>
<hobby>gaming</hobby>
<hobby>hiking</hobby>
</hobbies>
</person>YAML
# Person information
person:
name: John Doe
age: 30
email: [email protected]
hobbies:
- reading
- gaming
- hikingFeature Comparison
JSON Strengths
- Native JavaScript: Parsed with built-in JSON.parse()
- Universal API format: REST APIs standard
- Lightweight: Minimal syntax overhead
- Fast parsing: Simple grammar, optimized parsers
- Type support: strings, numbers, booleans, null, arrays, objects
XML Strengths
- XSD Schemas: Strict type validation
- Namespaces: Avoid naming conflicts
- XSLT: Transform documents
- XPath/XQuery: Powerful querying
- Document formats: DOCX, SVG, XHTML
- Attributes: Metadata on elements
YAML Strengths
- Comments: Documentation inline
- Human-readable: Minimal punctuation
- Multi-line strings: | and > syntax
- Anchors/aliases: Reuse content
- JSON superset: Valid JSON is valid YAML
Performance Comparison
| Metric | JSON | XML | YAML |
|---|---|---|---|
| Parse time (1KB) | ~0.1ms | ~0.8ms | ~0.5ms |
| Parse time (100KB) | ~5ms | ~40ms | ~25ms |
| Relative speed | ✅ 1x (baseline) | 8x slower | 5x slower |
| Browser support | ✅ Native | DOMParser | Needs library |
For performance-critical applications, see our YAML vs JSON performance benchmarks.
When to Use Each Format
✅ Use JSON When:
- Building REST APIs: Industry standard
- Web applications: Native JavaScript support
- Mobile apps: Smaller payloads
- Real-time data: Fast parsing matters
- NoSQL databases: MongoDB, CouchDB
✅ Use XML When:
- SOAP APIs: Enterprise web services
- Document formats: Office files, RSS, SVG
- Strict validation: XSD schema required
- Complex transformations: XSLT processing
- Legacy systems: Banking, healthcare
✅ Use YAML When:
- Configuration files: Docker, Kubernetes, CI/CD
- Human editing: Developers edit manually
- Documentation needed: Comments required
- API specs: OpenAPI/Swagger
- Infrastructure as code: Ansible, CloudFormation
| Use Case | Best Format | Why |
|---|---|---|
| REST API | JSON | Speed, JS native |
| Config file | YAML | Comments, readable |
| SOAP API | XML | Protocol requirement |
| Kubernetes | YAML | DevOps standard |
| SVG graphics | XML | Document format |
| package.json | JSON | npm requirement |
Frequently Asked Questions
What is the difference between JSON, XML, and YAML?
JSON uses braces and brackets, XML uses tags, and YAML uses indentation. JSON is lightweight and fast, XML is verbose but powerful with schemas, and YAML is human-readable with comment support. JSON dominates APIs, XML is used in enterprise, and YAML excels in config files.
Which is better: JSON, XML, or YAML?
It depends on your use case. JSON is best for APIs and web data. XML is best for enterprise systems needing strict validation and schemas. YAML is best for configuration files needing readability and comments. Choose based on requirements, not absolute preference.
Is JSON faster than XML?
Yes, JSON is significantly faster than XML to parse due to its simpler syntax. JSON files are also smaller because they don't require opening and closing tags. For high-performance applications like REST APIs, JSON is the standard choice over XML.
Why is XML still used if JSON is better?
XML offers features JSON lacks: namespaces for avoiding conflicts, XSD schemas for strict validation, XSLT for transformations, and XPath for querying. Enterprise systems, SOAP APIs, document formats (DOCX, SVG), and legacy systems still rely on XML.
Need to convert between formats?
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