wearable review

Oura Ring 4

Oura Ring 4 is a smart ring designed for 24/7 health tracking, providing insights into sleep, activity, stress, heart health, and women's health. It features a fully titanium design with recessed sensors and Smart Sensing for accuracy and comfort.

Published: Aug 9, 2026

Oura Ring 4

Best for

  • Sleep tracking and sleep stage analysis
  • Activity and fitness monitoring with automatic detection of 40+ activities
  • Stress monitoring and resilience tracking
  • Heart health insights including HRV, cardio capacity, and cardiovascular age
  • Women's health tracking with cycle insights and period prediction

Not for

  • Scuba diving or deep underwater use
  • Users who prefer a one-time purchase with no subscription

Why we landed here

Oura Ring 4 is a functional health-tracking device with research-grade sensors, a durable titanium design, and broad health insights across sleep, activity, stress, and heart health. It is a legitimate gadget rather than a gimmick, though it relies on a subscription for full feature access.

Pros

  • Fully titanium design with lightweight, durable construction
  • Recessed sensors on a fully round interior for comfort and non-allergenic wear
  • Smart Sensing adapts to your finger for accurate, continuous data
  • 5-8 day battery life with 20-80 minute charging
  • Water resistant up to 100m/328ft, suitable for sauna and water sports
  • Tracks sleep, activity, stress, heart health, and women's health
  • FSA/HSA eligible and compatible with iOS and Android

Cons

  • Full insights require an Oura Membership ($5.99/month or $69.99/year)
  • Not suitable for scuba diving despite 100m water resistance
  • Minor scratches from normal wear are considered normal

What matters in use

Our take

Oura Ring 4 is a fully titanium smart ring built around Smart Sensing, which adapts to your finger to deliver accurate, continuous health data. It tracks sleep stages, heart rate, HRV, blood oxygen, temperature trends, activity, and stress, with a 5-8 day battery and 100m water resistance that make 24/7 wear practical. The recessed sensors and non-allergenic interior are designed for all-day comfort, and the ring is available in multiple finishes. Full insights require an Oura Membership at $5.99/month or $69.99/year, and the device is FSA/HSA eligible.

Key details

Purpose
To track and interpret personal health signals through a wearable smart ring, delivering personalized insights for sleep, activity, readiness, stress, heart health, and cycle health.
Build quality
4.5 / 5
Practical utility
4.5 / 5
Value for money
4.5 / 5
Key feature 1
Smart Sensing platform with research-grade sensors
Key feature 2
24/7 heart rate, heart rate variability, and respiration rate monitoring
Key feature 3
Blood oxygen sensing (SpO2) during sleep
Key feature 4
Digital temperature trend sensor
Key feature 5
Accelerometer-based movement and activity tracking
Key feature 6
Readiness, Sleep, and Activity Scores
Key feature 7
Automatic activity detection for over 40 activities
Key feature 8
Bluetooth Low Energy connectivity with airplane mode
Key feature 9
Water resistant up to 100m/328ft
Key feature 10
Battery life of 5-8 days
Sizes
4-15
Width
7.90mm
Weight
3.3 to 5.2 grams (depending on ring size)
Sensors
Red and infrared LEDs for blood oxygen; green and infrared PPG for heart rate, HRV, and respiration; digital temperature sensor; accelerometer
Materials
Non-allergenic titanium inner and outer surfaces; PVD or DLC coating depending on finish
Thickness
2.88mm
Membership
$5.99 USD/month or $69.99 USD/year; first month free
Battery Life
5-8 days
Connectivity
Bluetooth Low Energy, EMF-safe, airplane mode, FCC certified
Charging Time
20-80 minutes
Compatibility
iOS and Android; integrates with 40+ apps
Water Resistance
100m / 328ft (not for diving)
Operating Temperature
-10 to 54°C / 14 to 129°F

Alternatives