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Front-Matter Editor & Validator — YAML Metadata, Checked Live

Edit and validate YAML front matter for Jekyll, Hugo, and static-site posts: types checked, required fields flagged, dates and booleans normalized.

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How to use Front-Matter Editor

  1. 1Paste your document with its --- front matter (the example is pre-loaded).
  2. 2Read the validation panel: every issue has a line number and a plain-language fix.
  3. 3Edit values in the key/value grid, or add the conventional fields (title, date, tags).
  4. 4Copy the re-serialized front matter back into your file — deterministic, clean ordering.

Front-Matter Editor FAQ

What exactly is validated?
Structure (opening ---, key: value pairs, closing ---), value types (strings, numbers, booleans, dates, quoted strings, inline arrays), duplicate keys, and common conventions (ISO 8601 dates, true/false booleans). Each issue carries a line number and a plain-language fix.
Is this a full YAML parser?
Deliberately no. It implements the flat-mapping subset that front matter actually uses — scalars and inline arrays — plus nested one-level keys used by some generators. Full YAML (anchors, multi-docs, block scalars) is out of scope and flagged rather than mis-parsed.
Does it support TOML (+++) or JSON front matter?
This phase validates YAML (---) fences — the format used by Jekyll, Hugo (default), and most static-site generators. TOML and JSON fences are recognized and reported as unsupported rather than silently failing.
Can I edit the values and get corrected output?
Yes. The editor parses your front matter into a key/value grid; edit values, add or remove keys, and copy back cleanly re-serialized front matter with deterministic key order.