What is the difference between YAML and JSON?

YAML uses indentation for structure and supports comments, anchors, and multi-line strings. JSON uses braces and brackets with no comment support. YAML is a superset of JSON — all valid JSON is valid YAML.

How do I fix "indentation" errors in YAML?

YAML requires consistent indentation (spaces only, never tabs). Use 2 spaces per level. Ensure child keys are indented further than their parent. Mixing tabs and spaces is the most common cause of YAML parse errors.

YAML Validator — Validate and Parse YAML

YAML input✓ Valid YAML

Parsed tree

name: "Yurlie"

version: "1.0.0"

server:

host: "localhost"

port: 8080

debug: false

database:

driver: "postgres"

host: "db"

port: 5432

name: "yurlie_db"

features: [

- "network-tools"

- "json-tools"

- "developer-tools"

]

config:

timeout: 30

max_connections: 100

cors_origins: [

- "https://yurlie.com"

- "http://localhost:3000"

]

Lines21

Root keys6

JSON size466 chars

What is YAML?

YAML (YAML Ain't Markup Language) is a human-readable data serialization format. It is commonly used for configuration files in DevOps and cloud-native tools: Docker Compose, Kubernetes manifests, Ansible playbooks, GitHub Actions workflows, and CI/CD pipelines (GitLab CI, CircleCI).

Common YAML Pitfalls

Tabs vs spaces: YAML only allows spaces for indentation. A single tab character will cause a parse error.
Unquoted strings: Values like yes, no, on, off are interpreted as booleans. Quote them if you mean the string literal.
Colons in values: A colon followed by a space (: ) starts a mapping. Use quotes for values containing colons, like "http://example.com".
Multi-line strings: Use | for literal blocks (preserves newlines) or > for folded blocks (joins lines with spaces).

YAML to JSON Conversion

Since YAML is a superset of JSON, every YAML document can be converted to JSON. This is useful when you need to feed YAML config to tools that only accept JSON, or when debugging complex nested structures in a more explicit format.

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