Processed locally — your file never leaves your device
YAML Validator
Check whether YAML is valid, with a clear message and location if it isn't — entirely in your browser.
How it works
- Paste YAML, or open a .yaml/.yml file.
- Click Validate.
- Read the confirmation, or the specific parse error if something is wrong.
Frequently asked questions
- Is my YAML sent to a server to be checked?
- No. Validation runs in your browser. This is the difference that matters for a Kubernetes manifest or a CI config, which often carries internal hostnames, image registries and job names.
- What does it check?
- YAML syntax: indentation, structure, quoting, anchors and aliases. A file that parses is well-formed YAML.
- Does it validate against a schema?
- No. It checks that the document is valid YAML, not that it matches what a particular tool expects. A syntactically perfect Kubernetes manifest with a misspelled field passes here and is still rejected by Kubernetes.
- Why does my file with tabs fail?
- The YAML specification forbids tab characters as indentation. Replacing leading tabs with spaces resolves it — this is the single most common cause of a file that looks correct but won't parse.
- Is it safe to check YAML from an untrusted source?
- Yes. The parser uses a safe schema that cannot instantiate arbitrary types or execute code, and alias expansion is capped so a maliciously crafted file can't exhaust memory.