A handful of small browser-based tools. Nothing novel — there are well-known incumbents for each of these — but each one is hand-coded, runs entirely client-side, and is here if you want it.
WCAG AA / AAA contrast checker for any colour pair. Live text preview at three sizes, plus a one-click "suggest a passing variation."
Paste a cron expression and get a plain-English explanation, the next few trigger times, and any common gotchas.
Pretty-print, minify, sort keys, or convert JSON to YAML or XML. Errors pinpoint to line and column.
Decode header and payload, see expiration timing, and verify signatures with HS256/384/512 secrets or RS256/384/512 public keys.
Paste a regular expression and see it as a railroad diagram. Live match testing, capture-group highlighting, and a plain-English breakdown.
Generate UUID v4, v7, and ULIDs in bulk. Decode a v7 to read its embedded timestamp. Copy one or copy all.