The Oura Ring 5 delivers meaningful refinements over its predecessor, notably a dramatically slimmer profile at just 2.28mm thick compared to 2.88mm on the Ring 4. More impressive is the weight reduction—Oura claims the heaviest Ring 5 size weighs less than the lightest Ring 4, making it feel more like jewelry than tech.

Design improvements include lower-profile sensors that maintain better skin contact, plus more powerful LEDs for enhanced accuracy in heart rate and blood oxygen monitoring. The new AI-powered Health Radar suite adds Blood Pressure Signs detection, though the overall feature set remains largely similar to Ring 4. Both models offer up to 9 days of battery life and 100-meter water resistance.

The catch lies in pricing and subscriptions. Oura Ring 5 starts at $399-$499 depending on finish, while Ring 4 begins at $349 with frequent discounts. Both require the same $5.99 monthly membership, a recurring cost that compounds the already steep upfront investment.

Ring 5 narrows size options from sizes 4-15 down to 6-13, eliminating choices for smaller or larger fingers. Despite superior comfort and some sensor upgrades, the combination of higher entry cost and mandatory subscription makes upgrading difficult to justify for existing users.

The Oura Ring 5 represents thoughtful iteration rather than revolutionary change, offering better wearability at the expense of accessibility.