YAML Formatter
Free online YAML formatter and validator — normalise indentation and catch YAML syntax errors in your browser. Nothing is uploaded.
Runs entirely in your browser — nothing you enter is uploaded or stored.
Validate and tidy YAML
Paste YAML from a CI config, Kubernetes manifest or app settings file and get back a clean, consistently indented version. If the document has a syntax error, the parser message points you to the exact spot.
Good to know
- YAML indentation must use spaces, never tabs.
- Formatting normalises quoting and key spacing, so diffs become smaller and cleaner.
- Parsing happens in your browser — secrets in your config never leave the page.
Credits
This tool is powered by open-source libraries that run in your browser:
- js-yaml — YAML parser/serializer (MIT)
Frequently asked questions
What does formatting do to my YAML?
It parses your YAML into an object and re-serialises it with consistent indentation and key ordering. That normalises spacing, removes noise and makes structural mistakes obvious.
Why do I get a YAML error?
Usually inconsistent indentation, a tab character (YAML forbids tabs for indentation), a missing colon, or unbalanced quotes. The parser message names the line and column so you can jump straight to it.
Can I change the indent width?
Yes — pick 2 or 4 spaces. Lines are wrapped at 120 characters to keep long strings readable.
Is my data uploaded?
No — everything runs locally in your browser. Nothing is uploaded.