To merge all of your duplicate contacts at once, you can use the Contact Merge Wizard tool. The wizard will go through all of your contacts, find the suggested duplicates, and let you merge them all with the touch of a button.
To get started, go to the Contacts page on the sidebar and click the arrow next to the "Add New" button at the top of the page. Click the "Contact Merge Wizard" to open the tool.
In the Contact Merge Wizard, there are 2 ways to filter the duplicates. You can choose to match them by Name or by Email with the toggle in the right corner.
Match Email, will bundle all contacts whose email addresses match.
Match Name, will bundle all the contacts whose names match.
You can choose to skip a contact by clicking the X button in the top right corner of their contact card. You can also choose which contact you want to be the main contact by clicking the Star icon in the top right corner of the contact card.
If you want to skip a contact entirely, click the X at the right of the Contact Header.
When you've managed each of your contacts, click the "Merge All" button at the bottom of the window to merge all of the contacts. The main contact will have its name, company name, username and address preserved if they're set.
Any contacts you merge into it will have their email, phone number and any additional fields copied into the new contact. Any contacts you merge into it will be deleted and the new contact will be the only contact remaining.
All Leads, Shoots, and/or Orders that any of the merged contacts were attached to, will be assigned to the new contact.