Yes, the Oura Ring 5 is noticeably smaller

From top to bottom: Oura Ring 5, Oura Ring 4 in ceramic, Oura Ring 4 regular, and Oura Ring Gen 3. This is not an Oura Ring 5 review. That's coming later, once I've had enough time to really test the new durability and battery life claims, plus the new software updates that start rolling out today. In the meantime, I did want to provide an answer to a burning question that I've seen asked in many Oura Ring comment sections across the internet. Yes, it is smaller and lighter than the Oura Ring 4.