Fix duplicate events from Outlook and Google sync tools

If you linked Outlook and Google with a third-party sync app, you may have ended up with two copies of the same meeting. Same title, same time, sometimes on both calendars. Manual cleanup does not scale once that spreads across months of events.

This guide is for that situation.

What went wrong

Most third-party sync tools copy events between calendars. They do not merge them into one shared event. So a team meeting in Outlook gets copied into Google, and now you have two separate entries for the same thing.

That is different from:

• getting invited twice by two organizers,
• a recurring series that was edited badly,
• or Google’s built-in “Add from URL” subscription calendars.

Sync-tool duplicates usually show up in pairs across Google and Outlook with nearly identical titles and times.

Stop the sync tool first

Before deleting anything, pause or uninstall the sync software that created the mess.

If you skip this step, the tool may recreate duplicates while you are cleaning, or bring back events you already removed.

Write down which calendar you treated as the source (Outlook to Google, or the other way around). You will need that when deciding which copy to keep.

Clean up with EventWipe

EventWipe reads your calendars directly. It does not run a background sync daemon, so you are not adding a third layer on top of the problem.

1. Connect both calendars

Open EventWipe and connect Google and Outlook with the accounts that have the duplicates. Load the calendars where the duplicate events live.

2. Let duplicate detection run

After events load, EventWipe groups likely duplicates for you. You will see them in a review modal with one row per group.

If you already dismissed that modal, look for duplicate-related rule suggestions or reconnect and reload events to surface the groups again.

3. Pick which copy to keep

For each group, keep one event and mark the rest for deletion.

A simple rule of thumb:

• keep the copy on the calendar you actually use day to day,
• if both are active, keep the copy on the calendar that was the sync source,
• when in doubt, keep the older entry and delete the newer clone.

Check the source label on each card. That makes it obvious whether a copy lives in Google or Outlook.

4. Review and delete

Check the deletion summary before confirming. EventWipe shows exactly what will be removed.

Run a smaller batch first if you have hundreds of duplicates. Once the results look right, finish the rest.

After cleanup

Open Google Calendar and Outlook side by side for a day or two. Confirm new meetings are not doubling up again.

If duplicates return, the sync tool is probably still running somewhere (another laptop, a background service, or a mobile app you forgot about). Turn it off completely before running another cleanup pass.

When not to use this workflow

If your company uses Microsoft 365 with a proper Google Workspace or Exchange federation setup, duplicates may come from IT configuration, not a consumer sync app. In that case, fix the integration with your admin before bulk deleting.

If you only have duplicates inside one calendar (same provider, no cross-sync), use title and date rules instead of the cross-calendar duplicate flow.

Quick checklist

1. Disable the third-party sync tool.
2. Connect Google and Outlook in EventWipe.
3. Review duplicate groups and keep one copy per meeting.
4. Delete the extras after previewing the list.
5. Watch both calendars for a few days to make sure nothing repopulates.