How it works
How to use the YAML Formatter
Paste YAML
Kubernetes manifests, Docker Compose, GitHub Actions, OpenAPI — anything.
Choose a style
Indentation, list indentation, block vs. inline collections and optional key sorting.
Fix errors
Syntax errors are underlined with their exact line and column.
Common YAML pitfalls
- Tabs are not allowed for indentation — use spaces.
- Inconsistent indentation changes the structure; siblings must line up exactly.
- Unquoted special values:
no,on,010and1e3may not mean what you expect — quote them. - Colons in values like
time: 12:30should be quoted.
Built for developers
Why developers use it
Private by design
Runs 100% in your browser. Nothing you paste is uploaded, logged or stored on a server.
Instant results
Output updates as you type, with precise error locations when something is wrong.
Works offline
Once loaded, the tool keeps working without a connection. Install it as an app if you like.
Free, no sign-up
No accounts, no limits, no watermarks.
FAQ
Frequently asked questions
Are comments preserved?
Yes. The formatter works on the YAML document structure, so comments stay attached to the nodes they describe.
Can I convert YAML to JSON?
Yes — use the JSON to YAML converter and switch the direction to YAML → JSON.
Is my data uploaded anywhere?
No. This tool runs entirely in your browser. Your input never leaves your device, is not logged, and works offline once the page has loaded.
Keep going
Related tools
- YAML ValidatorValidate YAML with exact error locations
- YAML ViewerExplore YAML as a collapsible tree
- YAML ParserParse YAML into a tree and JSON
- YAML to TSV ConverterConvert YAML lists to tab-separated values
- YAML to HTML Table ConverterConvert YAML lists to an HTML table
- JSON FormatterFormat, validate and explore JSON
- JSON to YAMLConvert JSON to YAML and YAML to JSON