DevToolKit

Crontab Guru — Parse & Explain Cron Expressions [2026]

Free cron expression parser. Paste a cron expression and get a human-readable explanation, next run times, and validation. Supports standard 5-field crontab syntax. 100% browser-based.

0
Minute
0-59
9
Hour
0-23
*
Day of Month
1-31
*
Month
1-12
1-5
Day of Week
0-7

Quick Presets

Syntax Reference

CharacterMeaningExample
*Any value* (every minute)
,List of values1,15,30
-Range of values1-5 (Mon to Fri)
/Step value*/15 (every 15)

What is Crontab Guru?

Crontab Guru is a free online tool that parses cron expressions and explains them in plain English. Cron expressions are used in Unix/Linux crontab, CI/CD pipelines (GitHub Actions, GitLab CI), Kubernetes CronJobs, and cloud schedulers (AWS EventBridge, GCP Cloud Scheduler) to define recurring schedules. This tool helps you verify that your cron expression means what you think it means.

How to Use Crontab Guru

1. Enter or paste a cron expression (5 fields: minute, hour, day-of-month, month, day-of-week). 2. The tool instantly shows a human-readable explanation of the schedule. 3. View the next 5 scheduled run times based on the expression. 4. Use the quick-select presets for common schedules like daily, weekly, or hourly. 5. Click any field to see its valid range and special characters.

How Crontab Guru Works

The tool parses each of the 5 cron fields (minute, hour, day-of-month, month, day-of-week) and interprets the values, ranges, steps, and special characters (*, /, -, ,). It then constructs a human-readable description by combining the field interpretations. Next run times are calculated by iterating forward from the current time and checking each minute against the cron expression constraints.

Common Use Cases

  • Verifying a cron expression before deploying a scheduled job
  • Understanding inherited cron schedules in legacy systems
  • Learning cron syntax by experimenting with expressions
  • Checking next run times for a production cron job
  • Validating cron expressions for CI/CD pipeline schedules

Frequently Asked Questions

What is a cron expression?▼

A cron expression is a string of 5 fields separated by spaces that defines a schedule. The fields are: minute (0-59), hour (0-23), day of month (1-31), month (1-12), and day of week (0-7, where 0 and 7 are Sunday). Special characters include * (any), / (step), - (range), and , (list).

What does */5 mean in a cron expression?▼

*/5 means "every 5 units." In the minute field, */5 means every 5 minutes (0, 5, 10, 15, ...). In the hour field, */5 means every 5 hours (0, 5, 10, 15, 20).

What is the difference between this and a cron generator?▼

A cron generator helps you build a cron expression by selecting options. Crontab Guru does the reverse: it takes an existing cron expression and explains what it does, shows next run times, and validates the syntax.

Is my data sent to a server?▼

No. All parsing and calculation happens entirely in your browser using JavaScript. Nothing is sent to any server.

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