How can I bulk delete thousands of my contacts in the new Outlook?

Question

I have about 20K contacts in my new Outlook and it is having great trouble displaying them. I want to clear all of them all out and import a far smaller (100) number of contacts. I cannot find a solution.

Answer 1

Hi EDW,

For New Outlook for Windows with a personal Outlook.com / Hotmail / Live account, the most reliable way to clean up a very large contact list is to manage the contacts directly in Outlook.com > People, since this is the primary contact store that New Outlook syncs from.

Before deleting anything, export your contacts to a CSV file so you have a backup.

Important: Deleting contacts from Outlook.com removes them from all Outlook apps that sync with this account.

Steps:

1. Sign in to https://outlook.live.com using the same Microsoft account.
2. Open People.
3. Delete the contacts in multiple rounds/pages. With very large lists, Outlook.com may not allow deleting everything at once, select all contacts on the current page, delete them, then repeat until the list is cleared.
4. Once the old contacts are gone, allow New Outlook some time to sync.
5. Use Import contacts to bring back only your smaller CSV file (for example, your ~100 contacts).

If the contacts are already gone on the web but still appear in New Outlook, close and reopen the app, then sign out and back in to force a refresh of the sync.

If you also have Classic Outlook for Windows installed, bulk deletion there is often faster for very large contact lists (for example, selecting all contacts at once and deleting them). This is optional, but can speed things up if you’re comfortable using it.

Finally, please let me know whether the contacts also appear in Outlook.com > People.

That will help confirm whether this is just a New Outlook sync/display issue or the full account contact list.

Please let me know if this proves useful to you, or if you would like further assistance.

I'm looking forward to your reply.

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Answer 2

To bulk clear contacts in new Outlook, use a classic client to select and delete them, then re-import the smaller list.

1. Open classic Outlook for Windows (or Outlook for Mac or Outlook mobile).
2. Go to People and select the contacts folder that holds the 20K contacts.
3. Press Ctrl+A (Windows) to select all contacts in that folder.
4. Press Delete (or right-click > Delete) to remove them.
   • Deleting from classic Outlook removes those contacts from all Outlook clients, including new Outlook.
5. Confirm that the contacts list in new Outlook is now empty.
6. Import the smaller (100-contact) CSV file into Outlook using the standard import process described in Import or export contacts in Outlook.

If duplicates or hidden copies exist, delete the contacts from new Outlook itself instead of classic Outlook; this removes the contact and all hidden duplicates from all Outlook apps.

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References:

• Manage duplicate contacts in Outlook
• Delete a contact in Outlook for Windows
• Microsoft 365 operated by 21vianet: Import contacts to Outlook for Windows
• Unable to edit Contacts, Appointments, Meetings, or Tasks within Outlook
• Manage contacts in Outlook