Understand and Test Cron Expressions
Paste a cron expression to get a plain-English description, the next five run times, and a field-by-field breakdown.
Enter a cron expression above, or choose a preset, to see its schedule explained.
About the Cron Expression Parser
Cron expressions are compact but hard to read at a glance. This tool decodes any 5-field or 6-field expression into a plain-English sentence, shows you exactly when it will run next, and breaks down each field so you can see precisely what's being matched.
Features:
- Plain-English descriptions in 6 languages
- Next 5 run times shown in your local timezone
- Supports standard 5-field and seconds-based 6-field syntax
- Ready-made presets for the most common schedules
How to Parse a Cron Expression
- Type or paste a cron expression, or pick one of the presets
- Toggle 6-field mode if your expression includes a seconds field
- Read the plain-English description of the schedule
- Check the next 5 run times and the field-by-field breakdown
Frequently Asked Questions
What is a cron expression?
A cron expression is a compact string used by schedulers to define when a task should run, made up of fields for minute, hour, day of month, month, and day of week.
What do the asterisks and slashes in a cron expression mean?
An asterisk (*) means “every value” for that field. A slash sets a step interval, like */15 for every 15 units; a hyphen defines a range like 1-5; and commas list specific values like 1,15,30.
Does this tool support a seconds field?
Yes — switch to 6-field mode and the first field becomes seconds (0-59), letting you schedule with sub-minute precision.
Are the next run times in my timezone or the server's?
They're calculated using your browser's local system clock and timezone, since everything runs client-side. If the job actually runs on a server in a different timezone, its real trigger times will differ from what's shown here.
Is my cron expression sent to a server?
No. Parsing, the description, and the next run times are all computed locally in your browser — nothing is uploaded.
What's the difference between 5-field and 6-field cron?
Standard cron uses 5 fields — minute, hour, day of month, month, and day of week. This tool's 6-field mode adds an optional seconds field at the very start for sub-minute precision, similar to what libraries like croner support.
Privacy
Your cron expression never leaves your browser — parsing and scheduling calculations all happen locally.