YAML Validator & Formatter
Validate YAML syntax, format documents, and convert to JSON. Features indentation checking and structure validation.
Syntax
Use 2 spaces for indentation. Keys end with a colon, values follow.
Data Types
Strings, numbers, booleans, null, arrays, and nested objects are supported.
Comments
Use # for comments. Comments are ignored during validation.
About the YAML Validator
This YAML validator checks a document for syntax and indentation errors, reports the line, and shows the parsed structure as JSON so you can confirm each key sits at the level you intended.
A YAML validator matters because YAML hides its mistakes. Indentation carries meaning, so a key indented two spaces too far becomes a child of the wrong parent — still perfectly valid YAML, just not what you meant. A pipeline then fails for reasons that look unrelated.
Seeing the parsed structure is what catches that class of error. The document might parse cleanly while a setting has landed under the wrong section, and only the resulting JSON makes the actual hierarchy obvious.
Tabs are the outright syntax error people hit most. YAML forbids tab characters for indentation entirely, and since an editor may render them identically to spaces the file looks correct while refusing to parse. Validation runs in your browser, so manifests containing internal hostnames stay local.
How to use the YAML Validator
- Paste your YAML. Enter the manifest, pipeline or config.
- Read the verdict. Valid, or the line where parsing failed.
- Check the parsed structure. Confirm every key sits under the parent you intended.
- Fix and revalidate. Correct indentation or remove tabs and check again.
YAML Validator features
- Syntax validation with line reporting
- Parsed structure shown as JSON
- Detects tab characters used for indentation
- Handles anchors, aliases and multi-line strings
- Works on Kubernetes and CI pipeline files
- Runs entirely in your browser
Frequently asked questions
Why does my YAML fail to parse?
Most often a tab character used for indentation, which YAML forbids entirely, or inconsistent indentation depth between sibling keys.
My YAML is valid but the setting is ignored. Why?
A key indented too far becomes a child of the wrong parent. That is still valid YAML, which is why the parsed structure view matters.
Can I use tabs to indent YAML?
No. YAML permits only spaces. Tabs are a syntax error even though many editors render them identically.
Does it handle anchors and multi-line strings?
Yes. Anchors, aliases and block scalars are all parsed and reflected in the structure view.
Is my manifest uploaded?
No. Validation happens entirely in your browser, so internal hostnames stay local.