YAML Formatter
Format, validate, and beautify YAML data instantly. Free online YAML formatter with key sorting.
Features
- ✓Format YAML with customizable indentation (2 or 4 spaces)
- ✓Sort keys alphabetically for consistent structure
- ✓Validate YAML syntax with clear error messages
- ✓Compact mode for minimal indentation
- ✓Works offline — no data sent to servers
- ✓Copy formatted output with one click
How to Use
- 1Paste your YAML data into the input field on the left
- 2Choose your preferred indentation size (2 or 4 spaces)
- 3Click "Format" to beautify or "Compact" to minimize indentation
- 4Optionally enable "Sort Keys" to alphabetize object keys
- 5Click "Copy" to copy the result to your clipboard
Examples
Input
server: host: localhost port: 8080 ssl: true database: name: myapp user: admin
Output
server: host: localhost port: 8080 ssl: true database: name: myapp user: admin
Input
zebra: last
apple: first
mango: middle
config:
zoom: 100
autosave: trueOutput
apple: first config: autosave: true zoom: 100 mango: middle zebra: last
What is a YAML Formatter?
YAML (YAML Ain't Markup Language) is a human-friendly data serialization format widely used for configuration files, CI/CD pipelines, Kubernetes manifests, Docker Compose files, and Ansible playbooks. Its clean, indentation-based syntax makes it popular among developers and DevOps engineers who need readable configuration without the verbosity of XML or the strict syntax of JSON.
A YAML formatter (also called a YAML beautifier or YAML prettifier) takes poorly indented or inconsistently formatted YAML and transforms it into a clean, consistently indented document. This is essential because YAML relies on whitespace for structure — a single misplaced space can change the meaning of your data or break your configuration entirely.
Our online YAML formatter validates your syntax in real-time, catching common errors like inconsistent indentation, invalid nesting, duplicate keys, and type mismatches. When working with complex Kubernetes deployments or multi-service Docker Compose files, catching these errors early saves significant debugging time.
The sort keys feature alphabetically orders all object keys at every nesting level. This is particularly useful for keeping configuration files consistent across teams, making diffs cleaner in version control, and following organizational standards. Many teams enforce sorted keys in their YAML files to reduce merge conflicts and improve readability.
Unlike online tools that upload your data to remote servers, this YAML formatter runs entirely in your browser. Your configuration files — which often contain sensitive information like database credentials, API keys, and infrastructure details — never leave your computer. No registration required, no data collection, just fast and private formatting.