Find duplicates in Google Contacts
I would like to remove duplicate contacts. My contacts run into thousands and merging is no small job.
Google recently introduced a new tool within gmail to merge duplicates. Full details on the this post from the official Gmail blog.
The export, clean up, and reimport fresh option is usually the easiest way to handle bulk editing of contacts.
The problem you'll run into with doing this is if you remove the contacts from your Contact list then anything linked to them will be gone even if you reimport the exact same information. An example would be your chat and google reader shares will be reset (I'm not sure about google docs because that one is based more on ID rather than communication options). So be wary if you have a lot of sharing or linked items with your contacts.
When reimporting, if the name matches then the import will merge wit the existing contact and just update the changed fields - if you have duplicate contacts though I'm not sure how this will be affected.
I have experienced the same thing before; I suggest you can try using duplicate remover like Scrubly Duplicate Remover. This works well for me. I assure you this will end up you’re duplicates problem.