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English → cron or regex.
Describe what you want in English. Get a tested cron expression or regex back.
How this works
- Cron mode: we ask Claude Sonnet for a 5-field POSIX cron + a timezone, then execute it with
cron-parserto show the next 5 firings. If parsing fails, you see the failure — we don't pretend. - Regex mode: the AI generates the pattern AND a set of test cases it thinks should match (and not match). We run those tests with
new RegExp()— if any fail, the regex is flagged as suspicious even if it compiled. - Catastrophic-backtracking guard: regex with nested unbounded quantifiers (like
(a+)+) is rejected before it can hang. We probe with a short input and a 100ms budget. - Deep links: every result has a one-click open into
crontab.guruorregex101so you can verify in a tool you already trust. - Privacy: descriptions are stored hashed for analytics. Raw paste lives 90 days for anon, lifetime for signed-in users. We never train on your data.