YAML
YAML Validator
Check mappings, sequences, scalars, anchors, and indentation locally with source-positioned errors.
How this tool works
Validate YAML syntax with normalized line and column issues.
Syntax validation does not prove a YAML document matches an application schema.
Examples
- Validate a CI configuration sample.
- Find an indentation error.
- Check bounded anchor and alias use.
Common use cases
Common mistakes
- Syntax validation does not prove a YAML document matches an application schema.
- Validate the output in the system that will consume it.
- Use synthetic data when sharing debugging evidence.
Privacy and limitations
Processing is local to this browser tab. Device, extension, clipboard, and shared-screen risks still apply, so redact secrets before using any browser tool.
Representative valid workflow
Valid example
Validate a CI configuration sample.
Expected: Use the tool output only after validating it in the receiving system.
Failure workflow
Invalid/failure example
Syntax validation does not prove a YAML document matches an application schema.
QA checklist
- Exercise a valid input.
- Exercise malformed or unsupported input.
- Verify copy or download output.
- Confirm the input remains local during the interaction.
Documented limitation
Syntax validation does not prove a YAML document matches an application schema.
Invalid or unsafe assumption
Invalid/failure example
A tab-indented mapping or inconsistent block indentation is rejected.
Mistakes to avoid
- Confusing YAML syntax with an application schema.
- Assuming visually similar scalars have the same type.
- Allowing unlimited alias expansion.
Limits of this workflow
Custom application tags and remote schemas are not interpreted.
Alias expansion is capped to protect the browser.
Local-processing and privacy boundary
YAML is parsed in the browser with a 2 MiB limit and is not sent to a backend.
Practical workflow
- Load YAML or type a synthetic example.
- Validate syntax and source positions.
- Review warnings and scalar types.
- Apply the consuming application's schema separately.
Official references
FAQ
Does the YAML Validator upload my input?
No. The operation runs in the browser and does not send tool input to a DevPouch processing service.
What are the limits of the YAML Validator?
Syntax validation does not prove a YAML document matches an application schema.
Does valid YAML guarantee a valid configuration?
No. The receiving system may impose additional schema, tag, and value rules.