You’re in control 

It’s easy for you to control how you want your Search history to be saved to your Google Account — including if you don’t want it saved at all. 

With auto-delete controls, you can choose to have Google automatically and continuously delete your Search history, along with other Web & App Activity, from your account after three, 18 or 36 months. For new accounts, the default auto-delete option for Web & App Activity is 18 months, but you can always choose to update your settings if you’d like. 

You can also try out a new way to quickly delete your last 15 minutes of saved Search history with the single tap of a button. This feature is available in the Google app for iOS, and is coming to the Android Google app later this year.

Source