Web of Science (WoS) and Scopus manually collect their data, and in general, they have more accuracy than Google Scholar (GS). However, GS tends to have more data coverage, and thus, citation counts tend to be higher in GS.
As a researcher and scholarly author, you can get a better idea of your total citation counts by cleaning up your GS profile and managing your list of publications and co-authors. Keep in mind that GS has come a long way since it was introduced in 2004.
WoS and Scopus have accuracy above the level of 99% while GS has an accuracy level above 95%. Read this blog post about GS being a serious alternative to WoS for more insight.
If you already have a Google/Gmail account, it is easy to set up an academic profile with Google Scholar (GS).
This 2-minute video will show you how to edit your GS profile and how to maintain an accurate list of your publications.
You can link your ORCID iD to your GS profile by simply adding the hyperlink of your ORCID iD in the Homepage field of your GS profile when you edit it. See the screenshot below for an illustration of this:
Be sure to manage your ORCID iD in order to get the most benefits out of this linking. GS can do a better job of linking your works to your ORCID iD if you manage the following on your ORCID iD:
Be patient though. It may take a few days for the linking to occur. If you are stumped, contact Rachel Miles at firstname.lastname@example.org