YAML Validator Online
Check your YAML for errors online and see the exact line of a wrong indent or a tab. Free, runs in your browser, nothing is uploaded.
How to use the YAML Validator Online
Validate, beautify and clean JSON, CSV, XML and YAML.
- Paste or upload your data
- Choose the options
- Copy or download the result
Tips
- Invalid JSON shows the exact line and column. “Auto-fix” repairs comments, trailing commas and single quotes.
- Numbers and key order are kept exactly as written – nothing is rounded.
- CSV: any delimiter is detected automatically; pick the one you want for the output.
- YAML: comments are kept, and you can convert YAML → JSON or paste JSON to get YAML.
Example
Input: name: demo
ports: 80
Output: Error at line 2: tabs are not allowed in YAML
Frequently asked questions
How do I validate YAML?
Paste it in. If it is valid you see clean YAML, and if not the line and the problem are shown.
Why are tabs not allowed?
YAML uses spaces for indentation. A tab makes the file invalid.
Guides