Paste one five-field cron expression. Read it in plain English, see its next runs, and check four platform rulebooks.
Common lists, ranges, steps, and three-letter names are supported.
Parsed expression
Read in the zone you pick, paired with UTC.Schedule rule: crontab(5)
Every scheduler here runs these UTC instants. Cloudflare and Vercel always evaluate cron in UTC. GitHub Actions and AWS EventBridge do too, unless you set a zone in their own configuration. Picking a zone here changes how the runs read, not when they happen.
One expression, four rulebooks. Syntax support does not include account or project limits.
Rules reviewed
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Straight answers about IndieCrontab: what the result means, what to do with it, and why there is no catch.
No asterisks hiding down hereA cron expression is a five-field schedule: minute, hour, day of month, month, and day of week, separated by spaces. * means every value, a list such as 1,15 names values, a range such as 9-17 spans them, and a step such as */15 repeats. The rules come from the Unix crontab(5) manual. IndieCrontab reads the expression, writes out what it means in plain words, and lists its next five runs.
It depends on the scheduler. Cloudflare Cron Triggers and Vercel Cron Jobs always evaluate the expression in UTC. GitHub Actions and AWS EventBridge Scheduler use UTC unless a timezone is configured there. A cron daemon on your own server uses that machine's zone.
IndieCrontab evaluates every expression in UTC and shows the five runs in your browser's zone, or any zone you pick, with the offset at each run. The picker changes how a run reads, never when it happens. When a clock change falls between two runs, the page says so.
In crontab(5), both do: the day of week field runs from 0 to 7, and 0 and 7 are both Sunday. The platforms disagree. GitHub Actions and Vercel document 0 through 6, so 7 is out of range there. Cloudflare numbers the week from 1 for Sunday through 7 for Saturday, so 0 is invalid and 1-5 means Sunday through Thursday. The three-letter names SUN through SAT keep one meaning everywhere except Vercel, which accepts numbers only. IndieCrontab names the problem in the platform row.
Each platform accepts a subset of crontab. Vercel refuses month and weekday names, weekday 7, and an expression that sets both day of month and day of week, and its Hobby plan runs a job once a day at an hour it picks within. GitHub Actions refuses weekday 7 and any schedule that runs more often than once every five minutes.
Cloudflare accepts five fields in UTC but numbers weekdays from 1 for Sunday, so a numeric weekday reads differently there. AWS EventBridge Scheduler wants cron(...) with a sixth year field, so every five-field expression needs a rewrite there. Every platform row names the rule it applied and links to the vendor page it rests on.
IndieCrontab reads the common five-field form: *, lists, inclusive ranges, steps, and three-letter month and weekday names. It does not read nicknames such as @daily or @hourly, a sixth seconds or year field, or the Quartz and AWS extensions L, W, #, and ?. Rewrite those into five fields first.
The platform rules were read from each vendor's own documentation on the date shown under the result. Plan limits and vendor rules change, so treat a row as a pointer to that page rather than a promise. The next runs are searched 80 years ahead at most, so an expression naming a date that never comes, such as day 31 of February, is refused.
Yes. No account, no card, no premium plan, no upgrade nag, no hidden paywall. IndieCrontab is free, all of it.
There is no public lookup history. A network check sends the public input needed for that check to its named source. Local file tools process file contents in your browser. Analytics is currently off, so no visit or job data is sent to a tracker. Anything the tool saves for you stays in your browser.