YAML Validator
Validate YAML syntax, catch indentation errors, and troubleshoot line-level issues quickly.
What this tool does
Validate YAML files and catch syntax problems before they break deployments or config loading. This tool flags indentation and parsing issues, helps you identify line-level failures faster, and supports formatter-assisted validation when you need clean, consistent YAML output.
Tool interface
Validate YAML Input
Validate YAML syntax, catch indentation issues early, and optionally format valid YAML before final checks.
YAML is indentation-sensitive. Use spaces consistently and avoid tabs in nested blocks.
Example input
version: 1
services:
api:
image: node:20
ports:
- 3000:3000Example output
Valid YAML. No syntax or indentation issues found.
Step-by-step instructions
- Paste YAML input or upload a `.yaml` / `.yml` file.
- Optionally enable Format before validate for normalized output.
- Run validation and review syntax errors with line-aware hints.
- Fix indentation and tabs/spaces issues, then validate again.
- Open YAML Formatter for additional cleanup if needed.
Common use cases
- Validating Kubernetes manifests before apply operations.
- Checking CI/CD YAML files for indentation and syntax errors.
- Reviewing app config YAML before deployment rollouts.
- Troubleshooting parser failures caused by tabs vs spaces.
Prevents runtime failures caused by malformed YAML in CI pipelines, infrastructure-as-code manifests, and app config files.
Common mistakes to avoid
- Mixing tabs and spaces in indentation.
- Forgetting list item markers (`-`) for sequence values.
- Using invalid key-value formatting in nested blocks.
- Assuming valid YAML syntax also guarantees schema correctness.
Frequently Asked Questions
How do I validate YAML online?
Paste YAML or upload a file, run validation, then fix reported syntax and indentation errors.
Can this tool catch indentation problems?
Yes. Indentation and nested-block structure errors are surfaced as parse failures.
Does this report line-aware YAML errors?
Yes. When parser details are available, line and column hints are shown to speed up fixes.
Can I format YAML before validating?
Yes. Enable Format before validate to normalize valid YAML before final checks.
What about tabs vs spaces?
YAML is space-sensitive. Tabs frequently cause parse issues, so this tool highlights indentation mistakes.
Can I validate Kubernetes YAML manifests?
Yes. It validates YAML syntax used by Kubernetes and other deployment manifests.
Does this YAML Validator check schemas?
No. It validates YAML syntax only. Use schema-specific tooling for semantic validation.
Does validation run in the browser?
Yes. Validation runs in-browser.
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