Where can I find the image search api?

Question

Google

How to check if an image is unique? those. if it is exactly the same image on the Internet.

Answer 1

Go to google pictures or yandex pictures - there is a photo icon in the search bar, it is designed to search by pictures.
Yandex assures that there is everything. Google is silent and just finds everything. But in any case, no one will give guarantees that nowhere is there exactly the same picture.