YAML Validator

This tool is a fast first-pass check for flat, top-level YAML key/value content: the kind of small configuration you hand-edit and want to glance over before committing. Think of a handful of settings like name, port, enabled, timeout — a service config snippet, an environment block, a feature-flag list, or a short metadata header pulled out of a larger file. If you have just typed or pasted a few lines and want to confirm they read as clean key/value pairs, this is the right size of task.

In practice it suits developers and ops folks doing a quick review inside the browser, students learning YAML syntax who want immediate feedback on whether their pairs parse, and anyone sharing a short config fragment who wants a basic look before sending it on. Because it runs entirely in your browser and keeps nothing after the tab closes, it is also reasonable for checking a config that contains internal hostnames or settings you would rather not paste into a remote service.

It is deliberately not a project-wide linter, a schema checker, or a replacement for your CI pipeline's YAML step. Its scope is the small, simple file or fragment — not a multi-document Kubernetes manifest, a CI workflow with nested jobs, or a Compose file with services and volumes.

The flow is paste, run, then copy or download. Paste your YAML into the input box and run the check (Ctrl or Cmd + Enter works as a shortcut). The tool reads each line top to bottom, looking for simple key: value pairs at the top level, and reports back a short confirmation when the content reads as well-formed simple key/value YAML. You can copy that result or download it as a text file. Nothing is uploaded; the parsing happens locally in the page.

Within a recognized pair it interprets common scalar types the way YAML does: true and false become booleans, null becomes a null value, plain numbers are read as numbers, and surrounding single or double quotes are stripped from strings. This mirrors how a small config would actually be consumed, so it catches the everyday case of a stray pair that does not split cleanly on its colon.

What it does not do is just as important. It does not validate nested mappings, list items written with dashes, anchors and aliases, multi-line block scalars, or document separators, and it does not judge whether your indentation is correct. The category label (yaml to text) reflects that the output here is a plain-text status line, not a converted data structure.

The biggest thing to understand: a line that does not look like a key/value pair is skipped rather than flagged. That means structure this tool does not understand — list entries, deeply indented blocks, anchors, or a malformed multi-line value — can pass quietly, and you may see a green-light message on content that a strict YAML parser would reject. A passing result here means your simple top-level pairs look fine, not that the whole document is valid.

Two specific mistakes follow from that. First, feeding it nested or list-based YAML and trusting the result; the nesting is essentially invisible to this check. Second, expecting it to catch indentation errors, duplicate keys across the document, or tab-versus-space problems — it does not enforce those rules. A value containing a colon or a hash can also be read differently than you intend, since those characters carry meaning in the matching.

Treat the confirmation as 'the simple pairs scan cleanly,' and remember the input box is the limit — there is no folder scan, no file picker, and no multi-document handling.

After running the check, re-read the source yourself: confirm every line you care about is an intended key: value pair, that keys are unique, and that booleans, null, and numbers were meant to be those types rather than strings. Look specifically at any nesting, dashed list items, or multi-line values, since those sit outside what this tool inspects — their presence does not mean they were validated. If you stripped quotes around a value, make sure the unquoted form still means what you want.

For anything authoritative — a production config, a deployment manifest, a file tied to financial, legal, or official systems — run it through a full YAML parser or your project's real validation step before trusting it. This in-browser check is a convenience pass for simple content, not a guarantee of correctness, so manual verification against your actual consumer remains the deciding test.