Explain a cron expression in plain English and see when it will actually run next.
Day of month and day of week are OR. When both are set, the job runs if either matches — so 0 0 1 * 1 fires on the 1st and every Monday, not only on Mondays that fall on the 1st. If one of them is *, only the other applies.
Run times are worked out in this browser’s timezone. On the day a clock shifts for daylight saving, a time inside the skipped hour does not exist; real cron daemons disagree about what to do then, so treat those days as approximate.
Format, validate and minify JSON in your browser — with the line, column and a plain-English reason when it will not parse.
Read the header and payload of a JSON Web Token, with its times explained. Decodes only — it does not verify the signature, and says so.
Test a regular expression against sample text, with every match highlighted and each capture group listed.
Generate UUID v4, v7 or v1, or Nano IDs — one or hundreds at a time, from your browser’s cryptographic random source.