Reply To: . Can I create a random `client_id` for GA4 events if `user_id` is already included?

[Ava]

The inclusion of both client_id and user_id in Google’s GA4 events might seem like an overlap, however, they serve different purposes. The client_id is used by Google Analytics to identify a unique browser or device, which is important for maintaining accuracy in session tracking. The user_id instead represents the unique ID of a user as recognized on your system, useful for identifying interactions of a specific user across multiple devices or sessions. Including a fake or random client_id could potentially interfere with this tracking and lead to inaccurate data, I wouldn’t recommend it. While the Google Analytics Help Center might not have specific resources on this, understanding how these IDs are used in tracking can help clarify their significance.