Confidence you can inspect
Exact and uncertain matches stay distinguishable, with details available before removal.
Calendar cleanup for macOSCalendar
CalendarDeduplicator
Find duplicate events, compare them clearly and remove only the copies you choose.
5duplicate groups found · 7 duplicate events
● Certain 3● High 2
Project kickoff3 copies · one kept
99Client presentation2 copies · review suggested
85Editorial planning2 similar events · you decide
55A careful cleanup, not a blind delete.
The app helps you understand every match before anything changes.
One event is always kept
CalendarDeduplicator marks the best copy and never includes it among the events to remove.
Simple and Expert modes
Use a guided review or detailed filters and batch controls when you need them.
Flexible time rules
Limit matches to the same day, require time overlap or inspect advanced cross-day cases.
Built for large calendars
Progressive analysis keeps the interface responsive while large result sets are processed.
Your choices remain visible
Review, select and confirm. Destructive actions stay explicit at every step.
From scan to clean calendar in three steps.
Choose and scan
Select a calendar and let the app analyze its events on your Mac.
Review the groups
Compare the copy to keep with the events proposed for removal.
Confirm safely
A backup is created before deletion, and immediate Undo is available.
Start free. Upgrade when the extra control matters.
The app presents the current subscription details and localized price directly from the Mac App Store.
Review before you remove
Scan and inspect duplicate groups with clear safeguards and a limited removal allowance.
Cleanup without the free limits
Unlimited removals, Keep Best, batch cleanup, backup and restore safety, and no 30-day deletion limit.
View on the Mac App StoreQuestions before you start?
Does the app delete anything automatically?
No. You review and confirm removals. The event marked Keep is protected from deletion.
What happens before a deletion?
The app creates a local backup. If the backup cannot be created, deletion does not proceed.
Can I reverse a cleanup?
Immediate Undo restores the events removed by the last completed operation. Saved backups can also be reviewed from the app.
Where can I get help?
Visit the support page or write to support@4191.ch.