Limit Sync for a SharePoint Site

To prevent the syncing all document libraries within a site:

1. On the site, click Settings > Site Settings.
2. Under Search, click Search and offline availability.
3. In the Offline Client Availability section, select No.

To allow people to sync files again, set the Offline Client Availability option to Yes.

To prevent syncing of a specific document library:

1. On the library, click Library Settings > Advanced Settings.
2. In the Offline Client Availability section, select No.
3. To allow people to sync files again, set the Offline Client Availability option to Yes.

Note the sync setting set at the site collection level overrides the setting at the library level.