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Cron Expression Generator
Cron Expression Generator — Visual Builder
Build cron expressions with a visual UI — see human-readable descriptions and next run times.
About Cron Expression Generator
Cron expressions define recurring schedules for automated tasks like database backups, report generation, cache clearing, and deployment pipelines — but the five-field syntax (minute, hour, day-of-month, month, day-of-week) can be confusing and error-prone. A misplaced asterisk or an off-by-one error can cause a job to run every minute instead of every hour, or skip days entirely. This tool eliminates that guesswork by letting you build cron expressions using visual dropdowns and toggles, or type an expression manually to see its human-readable description in plain English. It shows the next 5 scheduled run times calculated from the current moment, so you can verify that the schedule matches your intentions before deploying it. The tool supports standard 5-field cron format used by crontab on Linux/macOS, Kubernetes CronJobs, GitHub Actions scheduled workflows, AWS CloudWatch Events, and most task scheduling systems. Common schedules like 'every weekday at 9 AM,' 'first of every month,' and 'every 15 minutes' can be built in seconds.
Questions
Is my data sent to a server?
No. All processing happens locally in your browser. No data leaves your device.
What is a cron expression?
A cron expression is a string of five (or six) fields that defines a schedule: minute, hour, day of month, month, and day of week. It's used by Unix cron, CI/CD systems, and task schedulers to run jobs automatically.
What does * mean in a cron field?
An asterisk (*) means "every" — so * in the minute field means every minute, and * in the day-of-week field means every day. Other special characters include , (list), - (range), and / (step).
Does this show when the next runs will be?
Yes. The tool displays the next several scheduled run times so you can verify your cron expression triggers at the correct times.
What's the difference between 5-field and 6-field cron?
Standard Unix cron uses 5 fields (minute through day-of-week). Some systems like Quartz and AWS add a 6th field for seconds. This tool generates standard 5-field expressions.
Is my file uploaded to a server?
No. Transmute processes everything locally in your browser using JavaScript and WebAssembly. Your files never leave your device — there is no server, no upload, no cloud processing.