YAML validator
Paste a YAML file before pushing it to Kubernetes or GitHub Actions to catch errors early. When it passes you see its type, depth and value count.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter yaml text.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
The text is read line by line with YAML 1.2 rules for the supported subset, stopping at the first problem and naming its line. On success, depth is the number of nesting levels and values is the count of single values at every level.
Example
Result: Result: Valid YAML; Details: The whole document was read without errors; Top-level type: Mapping (keys and values).
Limits and caveats
- The tool supports a clear YAML subset: maps, lists, scalars, quoted strings, | and > block scalars and [ ] and { } flow collections. Anchors &, aliases *, tags ! and multiple documents are rejected with a clear message.
- It checks syntax only, not whether the fields match a Kubernetes or other schema.
Questions about this tool
Why does it reject a file another program accepts?
The file may use a feature outside the supported subset, such as anchors & or tags !. The message names the reason and the line.
Does it catch duplicate keys?
Yes. YAML does not allow the same key twice in one map, and the tool shows the repeated line.
Is my file sent to a server?
No. The whole check runs inside your browser.