Free Online Tool

YAML ↔ JSON Converter

Convert between YAML and JSON instantly in your browser

No data is sent to any server — everything runs client-side

YAML Input

Paste your YAML here

Input

JSON Output

Converted result

Output

What Is YAML?

YAML (YAML Ain't Markup Language) is a human-readable data serialization format that uses indentation to represent structure. Originally designed as a superset of JSON, YAML supports the same data types (strings, numbers, booleans, null, objects, arrays) but adds features like comments, multi-line strings, anchors/aliases, and custom tags.

YAML is the dominant configuration format in the cloud-native ecosystem: Kubernetes manifests, Docker Compose files, GitHub Actions workflows, Ansible playbooks, Helm charts, and CI/CD pipelines all use YAML. Its readability advantage over JSON comes at the cost of whitespace sensitivity — incorrect indentation silently changes the document's structure.

YAML vs JSON: Key Differences

FeatureYAMLJSON
Comments# comment✗ Not supported
Multi-line strings| and > operators✗ Escaped \n only
QuotingOptional for most stringsDouble quotes required
Anchors & aliases✓ Reusable data blocks
ReadabilityHigh (minimal syntax)Medium (braces & brackets)
Parsing speedSlower (complex grammar)Faster (simpler grammar)

When to Convert

Kubernetes & Docker

Convert K8s manifests or docker-compose.yml to JSON for programmatic manipulation with jq, API submissions, or language SDKs that only accept JSON.

CI/CD Pipelines

GitHub Actions, GitLab CI, and Azure Pipelines use YAML configs. Convert to JSON to debug parsing issues or generate configs programmatically.

API Payloads

Some APIs accept YAML (OpenAPI specs, CloudFormation). Convert between formats to match what your tools or clients expect.

Config Migration

Moving between tools that prefer different formats (e.g., JSON-based tsconfig.json to YAML-based equivalents or vice versa).

Common YAML Pitfalls

The Norway Problem

YAML 1.1 interprets NO, yes, on, off as booleans. Country code NO becomes false. Always quote ambiguous strings.

Tabs vs Spaces

YAML does not allow tabs for indentation — only spaces. Mixing tabs and spaces causes cryptic parsing errors.

Implicit typing

Values like 3.10 become the float 3.1, and 1e3 becomes 1000. Quote version numbers and similar strings.

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