How big must the random string be and how long should a user activation link be available?

As I see in this answer that cryptographically secure randomness is a must in user activation urls such as:
https://example.com/user-activate/^random_string^

But what are considered best practice regarding:

The length of the random strin… Continue reading How big must the random string be and how long should a user activation link be available?

How big must the random string be and how long should a user activation link be available?

As I see in this answer that cryptographically secure randomness is a must in user activation urls such as:
https://example.com/user-activate/^random_string^

But what are considered best practice regarding:

The length of the random strin… Continue reading How big must the random string be and how long should a user activation link be available?