Tool
YAML formatter and validator
Paste some YAML and get it tidied up and checked. Your comments stay put, your numbers stay exactly as you wrote them, and mistakes get a plain-English error with the line and column. Everything happens in your browser.
Nothing you enter here is sent or saved. Privacy policy
Paste some YAML on the left and the tidy version shows up here.
Good to know
Only the layout changes. Numbers are kept exactly as written: 0755 stays 0755 (turning it into 755 would change a file mode), and 12345678901234567890 keeps every digit. The tool reads its own result back and checks it still says the same thing, and if it can't be sure, it tells you rather than guessing.
Comments survive. That's the catch with many YAML tools: they parse the file, throw the comments away, and write out what's left. This one keeps them.
Yellow warnings are hints, not errors. They flag valid YAML that different tools read differently, like no (text to some, false to others), 0755 or 1.10. If your YAML is going into something old, they're worth a look.
Nothing leaves this page. Your YAML isn't sent, saved or put in the address bar. Handy for the configs that hold things you'd rather not paste into a random website.