JSON and YAML are two of the most popular data serialization formats. They look similar but have important differences in syntax, readability, and use cases. This guide compares them head-to-head.
1. The basics
JSON (JavaScript Object Notation) is a strict, lightweight format. It uses braces and brackets:{"name":"Alice","age":30}
YAML (YAML Ain't Markup Language) is a human-friendly format using indentation:name: Alice
age: 30
2. Key differences
- Syntax — JSON uses braces/brackets and commas; YAML uses indentation and colons
- Comments — YAML supports
#comments; JSON does not - Readability — YAML is more readable for humans; JSON is more predictable for machines
- Data types — YAML supports dates, binary, and references natively; JSON does not
3. When to use JSON
- APIs — the lingua franca of web APIs (REST, GraphQL, etc.)
- JavaScript apps — native to the language, no parsing needed
- Compact storage — minified JSON is smaller than YAML
4. When to use YAML
- Configuration files — Docker Compose, Kubernetes, GitHub Actions, Ansible
- Human-edited files — comments and indentation make it friendly
- CI/CD pipelines — most modern DevOps tools prefer YAML
5. How to convert between them
Open the JSON to YAML Converter and paste your JSON. The tool produces equivalent YAML, preserving structure and types. Useful when migrating configs.