Oura Ring 4 Review UK 2025: The Best Smart Ring Just Got Smarter

The Oura Ring 4 is the latest evolution of one of the most recognisable smart rings on the market. With improved comfort, refined aesthetics, and enhanced sensor technology, it builds meaningfully on its predecessors without radically changing the formula.

While it’s still not a full substitute for a high-end smartwatch when it comes to workouts, it remains the gold standard for effortless sleep and recovery tracking in an understated, screen-free form factor.

Oura Ring Design: From Tech Gadget to Wearable Jewellery

With the fourth-generation model, Oura has placed significant emphasis on aesthetics and wearability. The Oura Ring 4 features a sleek titanium body that replaces the plastic innards of Gen 3, resulting in a smoother, more refined finish. Available in six polished and brushed finishes—black, silver, gold, rose gold and others—the new design gives the ring the appearance of minimalist jewellery rather than a chunk of wearable tech.

The ring still measures about 3mm in thickness, making it twice as thick as a typical wedding band, but many users may now be able to size down thanks to its more ergonomic interior. The three sensor bumps that previously protruded on the inner surface are gone, replaced by a flush array of dark windows and two almost imperceptible bumps. This change dramatically improves comfort and makes the ring easier to wear throughout the day—and night.

At 3.3g to 5.2g, depending on size, the Oura Ring 4 remains exceptionally lightweight. The expanded sizing range (now 4 to 15) also improves accessibility and fit for a broader range of users.

Sensor & Hardware Upgrades: Smarter from the Inside Out

The Oura Ring 4's hardware has been overhauled to improve tracking accuracy and usability. Internally, it now houses an enhanced set of sensors:

• Green and red LEDs for heart rate and heart rate variability

• Infrared sensors for blood oxygen (SpO2) measurement

• Digital temperature sensors for continuous BBT monitoring

• 3D accelerometer for motion and activity detection

These sensors are now asymmetrically positioned within the ring, allowing for more accurate readings regardless of how the ring shifts on the finger. Oura has also increased the number of optical signal pathways from 8 to 18, which enables the ring to adjust to different skin tones, finger shapes, and movement conditions dynamically.

In practice, this means less fiddling and repositioning and more reliable data across varied activities, including sleep, walking, hiking, and even water-based activities—the ring is waterproof to 100 metres.

Oura Ring Battery Life & Charging

Battery performance has also seen modest but meaningful improvements. Most users can expect between five to six days of use between charges—around a day longer than Gen 3. The ring is charged via a newly designed charging puck that is sturdier and more stable on surfaces than its predecessor. A full charge takes roughly 80 minutes.

One notable downside is the lack of backward compatibility for Gen 3 chargers, and—perhaps more concerning in the long term—the ring remains non-repairable, with no battery replacement options available. Oura doesn’t publish an expected battery lifespan but claims at least 80% capacity after 500 full charge cycles.

Software: A Much-Improved App Experience

Oura’s accompanying app, available on both iOS and Android, has undergone a significant redesign to better handle the increasing depth of metrics the ring can track. Key features include:

• Today Tab: Displays real-time data such as stress, activity, heart rate, and tags for daily events like meals or workouts.

• Vitals Tab: Aggregates core metrics under umbrella categories like Readiness and Sleep, with clear visuals and baseline comparisons.

• My Health Tab: Offers long-term trend data, including cardiovascular age, recovery patterns, and chronotype insights.

The new layout is intuitive and well-organised, with easy navigation between data points. Charts and metrics are colour-coded for stress levels, and a subtle haptic integration syncs to your phone's vibration for heart rate pulses.

New Features: AI and Smart Logging

Among the most interesting additions is the Oura Timeline, a daily view of tracked events and behaviours that can be tagged manually for deeper behavioural insights. For example, users can tag meals, workouts, or rest periods, and the app builds a timeline of physiological responses.

One standout beta feature is Meals, available through the experimental Oura Labs tab. This allows users to upload photos of their meals, which are then analysed by AI to assess dietary patterns and sync meal timing with one's chronotype. While the feature takes several days to calibrate, it hints at a future where the Oura ecosystem may serve as a more comprehensive wellness assistant—not just a sleep tracker.

Another addition is the Oura Advisor, a built-in AI assistant that offers data-driven health advice, checks in via phone notifications, and suggests actions to improve recovery or productivity. While still in its early stages, it shows potential for those looking for guided insights without hiring a health coach.

Oura Ring Sleep Tracking: Still the Best in Class

Despite the increasing competition from smartwatches and newer rings like the Samsung Galaxy Ring or Ultrahuman Ring Air, Oura still leads in sleep tracking accuracy and depth.

The Ring 4 continues to track:

• Sleep stages (light, deep, REM)

• Sleep onset and wake time

• Sleep efficiency and latency

• Nighttime HR and HRV

• Breathing rate and body temperature fluctuations

Oura’s Readiness Score remains a highlight, combining sleep quality, recent activity, HRV trends, and temperature to deliver a daily indication of how well-prepared the body is for physical or cognitive exertion.

While activity tracking remains basic (steps, calorie estimation, workout logging), the ring can auto-detect over 40 types of movement and now imports data from third-party apps like Strava for a fuller picture of total exertion.

Oura Ring 4 Subscription Model & Price

The Oura Ring 4 is priced at £349, with additional finishes commanding higher prices. A subscription is required to access anything beyond very basic metrics, costing £5.99 per month or £69.99 annually.

This makes the Oura Ring one of the more expensive options on the market, particularly when considering that devices like the Apple Watch SE start at a lower upfront price and don’t require a subscription for basic health tracking.

The Verdict: Subtle, Sophisticated, and Still Leading the Pack

The Oura Ring 4 represents a thoughtful refinement rather than a revolutionary leap—but the changes are significant. Its improved fit, enhanced comfort, upgraded sensors, and more intuitive app make it one of the most discreet yet powerful health tracking devices available.

However, its non-repairable nature and required subscription continue to be drawbacks. And while it excels in sleep, recovery, and passive health tracking, those seeking comprehensive workout metrics will still need a smartwatch or dedicated sports device.

For users wanting advanced health insights without the bulk of a wrist-based tracker, and with a design that complements rather than clashes with daily wear, the Oura Ring 4 remains a top-tier option.

Rating: 9/10

Pros:

• Stylish and discreet

• Best-in-class sleep and readiness tracking

• Improved comfort and size options

• Enhanced sensor accuracy

• Up to six days battery life

• Excellent app interface and trend analysis

• Waterproof to 100 metres

Cons:

• Expensive

• Monthly subscription required

• Limited workout tracking

• Battery is non-replaceable

• No repairability or recycling programme

Availability

• £349 at John Lewis

• £349 at Amazon UK