Samsung has already released a subset of the Galaxy AI features for the Galaxy S21, S21+, and S21 Ultra, and that of course includes Circle to Search. However, the Galaxy S21 FE did not receive Circle to Search at the time, despite sharing its chipset with the other members of the S21 family.
This bug has finally been fixed. Samsung has brought Circle to Search to the Galaxy S21 FE as part of the August 2024 security update, which is currently rolling out in Vietnam and should be rolling out to other markets in the next few days. It also fixes over 50 security flaws in Android and Samsung’s One UI.
As you probably already know, Circle to Search does exactly what its name suggests. It lets you circle anything on your screen and get information about it. You can even find out what song is playing nearby (or on your phone). You bring up Circle to Search by long-pressing the white bottom bar of the pill, or the Home button if you still have it.
Source
