Oura Ring 4 is the next evolution of the revolutionary smart ring, designed to help you get up close and personal with your health. Oura Ring 4 is built around a breakthrough sensing technology, Smart Sensing, which is powered by an algorithm that works with research-grade sensors to dynamically adapt to the finger and deliver accurate and continuous data, day and night. See Oura Ring FAQs here.
Here's how Oura Ring 4 compares to Oura Ring Gen3 .
Oura Ring 4 Oura Ring Gen3
Style 2 styles: Heritage and Horizon
Design & Material
Fully titanium exterior & interior
Recessed interior sensors at 0.3mm
Titanium exterior, epoxy interior
Raised interior domes (sensors) at 1.3mm
Finishes
Black
Brushed Silver
Gold
Silver
Stealth
Rose Gold
Black
Brushed Titanium (Horizon only)
Gold
Silver
Stealth
Rose Gold (Horizon only)
Sensing Platform Accuracy is powered by Smart Sensing that dynamically selects the optimal signal path Measurements powered by a fixed, static configuration of optical paths
Sizing
Battery
Charging Time Typically between 20-80 minutes depending on the ring starting charge level Typically between 20-80 minutes depending on the ring starting charge level
Charger
Grey and square
USB-C to USB-C
Black and circular
USB C to USB 2.0 standard-A cable
Sensors
Red and infrared LEDs measure blood oxygen levels while you sleep
Green and infrared LEDs alternate to measure heart rate 24/7 and heart rate variability and respiration rate during your sleep
Digital sensor measures your temperature variations
Accelerometer tracks movement and activity 24/7
Red LEDs measure blood oxygen levels while you sleep
Green LEDs monitor heart rate 24/7
PPG sensors read resting heart rate, heart rate variability, and respiration
NTC sensors monitor your nighttime skin temperature trends
Accelerometer tracks movement and activity 24/7
Dimensions
Width: 7.9mm
Thickness: ~2.88mm
Weight: 3.3-5.2 grams (depending on ring size)
Width: 7.9mm
Thickness: ~2.7mm (Heritage), ~2.9mm (Horizon)
Weight: 4-6 grams (depending on ring size)
Water Resistance 100m/328ft, suitable for sauna and water sports but not diving 100m/328ft, suitable for sauna and water sports but not diving
Operating Temperature
-10–54 ºC / 14–129 ºF
Charging at room temperature recommended
-10°C–52°C / 14°F–125°F
Charging at room temperature recommended
