FAQ (Frequently Asked Questions)

About the project

1. What is (and is not) Google-4-TbSync?
   • Google-4-TbSync is a Thunderbird add-on used to synchronize your Google Contacts addressbook(s) with your local Thunderbird installation.
   • Google-4-TbSync does not provide calendar synchronization, and will probably never do because there is no need to: a good support is already provided by Thunderbird itself or other add-ons through the standard CalDAV protocol.
2. Is Google-4-TbSync the same as, or a replacement for, TbSync?
   • Google-4-TbSync is, technically, an add-on to TbSync, which in its turn is an add-on to Thunderbird.
   • As a consequence, you will need to install Thunderbird first, then TbSync, then Google-4-TbSync.
3. Do we need another Google synchronization add-on?
   • Short answer: yes. Long answer here.
4. Why do I need to create my own Google Cloud Console project credentials? Can't they be stored into Google-4-TbSync like other applications or add-ons do?
   • Google-4-TbSync is an open source project; consequently, hardcoding the Google credentials into the code would still leave them in clear, which apparently is forbidden by Google. Unfortunately, you will have to create them by yourself.

Technical issues

5. How can I create my own Google Cloud Console project credentials?
   • Answer here.
6. Where can I find the meaning for all the options?
   • Answer here.
7. I receive a "401: invalid_client" error. What could it be?
   • Most probably you forgot to create the Google credentials, or you made some mistake in the creation process. Please check back all the steps in this guide.
8. I receive a "403: access_denied" error. What could it be?
   • Most probably you (as a Google developer) forgot to authorize yourself (as a Google user) when creating the Google credentials. In other words, when following this guide, add yourself at step "4 > Test users".
9. Google-4-TbSync 0.4.x has become much slower.
   • This is a known issue, and investigation is ongoing about the possible reasons. The issue can be mitigated by turning off the Include system contact groups and Verbose logging options, and above all by upgrading to the 0.5.x version whose engine was partly rewritten and appears to be much faster, especially when updating an addressbook.