Free Cron Expression Builder & Generator Online
A cron expression is the tiny five-field code that tells a server when to run a job — “every day at 6am,” “every Monday,” “on the 1st of the month.” The five fields are minute, hour, day-of-month, month, and day-of-week. They're powerful but easy to misread, so this tool lets you build one visually and shows the next run times, and it decodes an existing expression into plain English.
Frequently Asked Questions
- What is a cron expression?
- A cron expression is a string of five space-separated fields that define a recurring schedule: minute, hour, day-of-month, month, and day-of-week.
- What does * mean in a cron field?
- An asterisk (*) means 'every' — so * in the minute field means the job runs every minute of the hour.
- How do I run a job every 15 minutes?
- Use */15 in the minute field: '*/15 * * * *' runs the job at minutes 0, 15, 30, and 45 of every hour.