YAML Validator
Check YAML syntax and see the parsed structure as JSON.
A single wrong indent in a YAML file can break a deployment or a CI run. The YAML Validator in HackUtilities parses your document, shows the parser error if there is one, and otherwise displays the data structure as JSON so you can confirm it reads the way you intended. Config files often hold hostnames and secrets, so parsing them locally is safer than pasting them into a web form.
Syntax validation
The document is parsed with js-yaml. A status badge shows Valid YAML or Invalid YAML, and errors include the message from the parser.
Parsed structure as JSON
Valid input is shown as pretty-printed JSON, which makes it easy to see how anchors, nesting and types such as numbers, booleans and strings were interpreted.
Copy JSON
Copy the parsed result to the clipboard as JSON with one button.
Sample and reference
Load a sample document to try the tool, and use the built-in YAML syntax reference below the editor.
Character and line counts
The input pane shows how many characters and lines you have pasted.
Does the YAML Validator check against a schema?
No. It checks that the document is valid YAML and shows what it parses to. It does not validate keys or values against a schema such as Kubernetes or GitHub Actions.
Is my YAML uploaded anywhere?
No. Parsing happens inside the app on your computer, and the tool does not make network requests.
Convert between YAML and JSON with control over indentation and style.
Open →Format, validate and minify JSON with 2, 4 or 8 space indentation.
Open →Side-by-side text diff with word-level highlights and a JSON mode.
Open →No card, no account. Every tool included, bought once.