This feature is for the Google Users.
Google Apps users can refer to Zoho CRM for G Suite Users​

Keeping up-to-date contacts in both Zoho CRM and Google Contacts is now made easy with the Contacts Synchronization feature. It helps you to configure one-way or two-way sync schedules that will automatically sync contact details. Also, you can specify the list to which the contacts should be transferred and map fields as required. 

To configure synchronization settings

1. Log in to Zoho CRM.
   
2. In Zoho CRM, go to Setup > Marketplace > Google > Contacts.
   
3. In the Contacts Synchronization page, do the following:
   
4. Choose the Google Contact list and the Zoho CRM Contacts list from the drop-down.
   The contacts from the selected lists will be synchronized.
   
   
   
5. Choose one of the  Sync Options.
   
   • 2 Way Sync
     
   • 1-Way: Zoho CRM Contacts to Google Contacts
     
   • 1-Way: Google Contacts to Zoho CRM Contacts
     
6. Select one of the following option when there is a conflict in contacts in both the places.
   
   • Zoho CRM contact will overwrite the Google contact
     
   • Google contact will overwrite the Zoho CRM contact
     
7. Choose the synchronization Frequency from the drop--down list.
   
8. Map the fields in Google and Zoho CRM.
   
9. Click the Map More Fields link, to add more field and map them.
   
   
10. Click Save.
    

Note:

• Synchronization Limits:
  
• Google to CRM: First time you can synchronize maximum 25,000 contacts. For the consecutive syncs, maximum 5000 contacts will be synchronized.
  
• CRM to Google: First time you can synchronize maximum 25,000 contacts. For the consecutive syncs, maximum 1000 contacts will be synchronized.
  
• The synchronization of contacts from Zoho CRM to Google and vice versa will take a while to complete based on the number of contacts. We request you to wait for a few minutes and then check if the contacts have been synchronized.
  
• Check the Last Sync Time in the Contacts Synchronization page to see if the sync was performed.
  
• Note that only the contacts of the selected Google Group and the selected Zoho CRM List View will be synchronized. The contacts from CRM will be added in the specified Google Group.
  
• Based on the roles and access privileges, the contacts will be synchronized.
  
• Please note that if you delete the sync configurations and again synchronize the contacts, then duplicate records will not be created in the case of Google contacts to Zoho CRM contacts sync as it is based on the email address that is mapped. However, if the sync is from Zoho CRM contacts to Google contacts then duplicates will be created.
• The criteria to search duplicate records are based on the Email field value (primary email field in contacts) in Zoho CRM and Email (Work) field value in Google Contacts. (Google Contacts to Zoho CRM Contacts sync only)
  
• If Email is empty then duplicates will be created in Zoho CRM contacts and Google contacts every time a sync happens.

To deactivate the contacts synchronization

1. Log in to Zoho CRM.
   
2. In Zoho CRM, go to Setup > Marketplace > Google > Contacts.
   
3. In the Contacts Synchronization page, click the Deactivate link.
   You can revoke the Google authentication from https://accounts.google.com/