Fortunately, you don't have to. Whether importing went haywire, you deleted a contact without meaning to do that or synchronizing your Gmail contacts with your phone messed up the whole shebang, you need not worry if any of that happened in the last 30 days.
That's how long Gmail keeps automatically created backup snapshots for your Gmail address book. Restoring your entire Gmail contacts to the state in which it was at any point within that time is — a snap.
Restore Your Gmail Contacts to a Previous State from Backups Kept Automatically for You
To recover the state of your Gmail contacts from any point in the last 30 days:
- Go to Contacts in Gmail.
- If you cannot see Contacts beneath Mail in Gmail's left navigation bar, click the + sign that appears next to Mail when you position the mouse cursor over it.
- Click More actions.
- Select Restore contacts… from the menu.
- Pick the desired point in time under Please select a time to restore to:.
- Note that anything that happened to your contacts since then will be undone. Contacts you may have deleted will be restored; contacts you have added or imported will disappear.
- See below for exporting and re-importing any added contacts you want to preserve.
- Click Restore.
Preserve Recently Added Contacts Beyond Gmail Address Book Restoration
To export contacts you have added after the point to which you will restore your Gmail address book:
- Select New Group… in the left navigation bar.
- Enter a name for the group such as "contacts to be re-imported".
- Click OK.
- For all contacts you want to re-import:
- Search for or spot the desired contact.
- Make sure it is checked.
- Click Groups.
- Make sure the "contacts to be re-imported" group is checked.
- Click Apply if necessary.
- Now click More actions.
- Select Export… from the menu.
- Make sure The group contacts to be re-imported is selected under Which contacts do you want to export?.
- Select Google CVS under Which export format?.
- Click Export.
After restoring your Gmail contacts to a previous state (see above), to recover wanted entries you may have lost during the process:
- Click More actions… in Gmail Contacts.
- Select Import… from the menu.
- Find and select the "google.csv" file you previously saved under Please select a CSV or vCard file to upload:.
- Click Import.
- Now click OK.