I came across an interesting article via Reddit, but to my surprise it was taken offline by the page hosting it, Medium.com, for reasons unknown. Luckily someone on that Reddit thread saved the main link. Click and find out for yourself.
https://www.google.com/ads/preferences/ – Ad preferences
https://maps.google.com/locationhistory – Where you’ve been
https://history.google.com – Search history
https://security.google.com/settings/security/activity – Devices you’ve used
https://security.google.com/settings/security/permissions – Apps that use your info
https://www.google.com/takeout – Export your data
What does Google know about you?
via 6 links that will show you what Google knows about you : technology.
Here’s an additional “mirror”