One wrong space breaks a YAML file. Paste a Docker Compose file, GitHub Actions workflow, Kubernetes manifest or any config, and see whether it is valid, with the exact line and column of any error. It also warns about traps such as tabs, missing spaces after colons and words like “no” that some tools read as false, and shows the parsed data as JSON so you can see what the program will get.
loading toolHow to use the yaml validator
- Paste your code into the box (or tap Try a sample).
- Read the list of problems: ✕ marks an error, ! a warning.
- Tap Show next to a problem to jump to that line, fix it, and watch the list update.
Good to know
- Items in the same list or map must line up exactly.
- Put strings with : # or a leading * in quotes.
Questions
What is the “Norway problem”?
In older YAML (version 1.1), unquoted yes, no, on and off mean true or false, so the country code NO becomes false. Put such values in quotes to be safe.
Can YAML use tabs?
No. YAML indents with spaces only; a tab is always an error.
Is my data private?
Yes. Everything happens inside your own browser: nothing you type or choose is uploaded to us or anyone else.
Is it free?
Completely free, with no sign-up, no watermark and no limit on how many times you use it. Light ads keep the site running.
