The Oura Ring 4 is here—and it’s more than just a pretty ring. With a sleek, screenless design and powerful health-tracking features packed into a discreet titanium band, the fourth-generation Oura Ring is built for people who want accurate sleep tracking, 24/7 health monitoring, and daily recovery insights without the bulk of a smartwatch. From advanced biometric sensors to a refined, ultra-comfortable design, Oura Ring 4 offers a smarter way to track heart rate, temperature, blood oxygen (SpO₂), sleep stages, and overall readiness. But does it justify its premium price and subscription model? In this in-depth review, we’ll explore the Oura Ring 4’s features, performance, battery life, app experience, and how it compares to leading wearables like the Apple Watch, Fitbit, and WHOOP.
Whether you’re focused on recovery, stress management, or fertility awareness, this blog covers everything you need to know before buying the Oura Ring Gen4 in 2025.
Table of Contents
1. Design and Comfort
The new design has no raised sensor bumps (they’re now recessed inside), allowing it to sit flush against the finger. It comes in six finishes (including a new brushed silver) and sizes 4–15 (versus 6–13 on Gen3). Reviewers note it feels “super comfortable” to wear around the clock, and is rated waterproof to 100 m, so you can shower or swim with it. A compact new charging puck (USB-C) powers the ring to full in about 1 hour. The Gen4 ring is also slightly thinner and lighter than Gen3 (2.88 mm vs ~2.9 mm), and its fully rounded titanium design makes it feel more like jewelry.
2. Sensors and Hardware
The Ring 4 packs advanced biowearable sensors. Onboard are multiple LEDs and photodiodes (red, infrared, and green) for measuring heart rate, heart-rate variability (HRV), blood oxygen (SpO₂), and blood-volume changes, as well as a new fast-response digital temperature sensor and a 3-axis accelerometer. Oura’s new Smart Sensing platform uses 18 sensor pathways and adaptive algorithms to continuously optimize readings even if the ring shifts position. In practice, this means more reliable data when your finger moves or isn’t perfectly aligned. The internal sensor bumps have been reduced from 1.3 mm (Gen3) to 0.3 mm, improving comfort and allowing a slighter profile. All components and sensors are now encased in hypoallergenic titanium (previous Gen3 rings had an epoxy interior). Because of this hardware upgrade, Oura claims much higher signal quality: in internal tests, they reported ~120% better SpO₂ signal quality (30% higher accuracy) and significantly fewer missing data gaps in the heart-rate record.
3. Sleep Tracking and Readiness
The Oura Ring has long been celebrated for sleep analysis, and Gen4 continues this. Every morning the app provides a Sleep Score (0–100) and a detailed breakdown of sleep stages (REM, deep, light) and metrics like total sleep time, efficiency, restfulness, and respiratory/breathing regularity. In independent lab tests against polysomnography (the gold standard), Oura’s sleep-staging was more accurate than Apple Watch and Fitbit: one study found Gen3 Oura was 5–10% more accurate overall and had the highest sensitivity for deep sleep (79.5%) and wake detection. In practical reviews, TechRadar reported Oura’s sleep tracking was “highly accurate,” correctly detecting wake periods and sleep quality in realistic scenarios. Users on Amazon similarly praise the sleep data – for example, one noted the ring’s sleep score matched their own experience of tossing and turning vs sleeping soundly. The Ring also detects breathing disturbances (apneas) and blood-oxygen drops during sleep, which can signal snoring or sleep apnea. All sleep data feeds into a Readiness Score: a composite 0–100 index of how recovered you are. Oura’s Readiness Score algorithm uses your recent activity, sleep history, resting HR, HRV, and body temperature to assess if you’re “ready for action” or need rest. (For example, a score ≥85 is “Optimal,” 70–84 is “Good,” and <70 suggests you may need more recovery.) This holistic metric is unique to Oura and valued by users who want daily recovery guidance.
4. Activity Tracking and Workouts
Oura 4 tracks basic daily activity (steps, calories, distance, and active minutes) using the accelerometer, and it now auto-detects many workout types. According to Oura, the new ring can recognize up to 40 different exercise profiles (if you indicate your common workouts). In testing, it picked up runs and hikes automatically, giving calorie and heart-rate data comparable to a sports watch (though it lacks GPS or stride sensors). (The Wired review found Oura recorded six hikes on a weekend, whereas a Garmin Fenix only logged three.) However, without onboard GPS or a display,y you won’t get real-time pace or mapping – any outdoor run uses your phone’s GPS via the companion app. For most casual users, this is fine, but serious athletes may miss exact metrics. Unlike Whoop, Oura does record steps and distance (Whoop tracks strain instead). Oura also monitors 24/7 heart rate and HRV, and includes features to gauge stress resistance (a new “stress” score) and Resilience level.
5. Temperature Sensing
A standout new sensor in Gen4 is the continuous body temperature monitor. The digital temperature sensor tracks your finger’s skin temperature, especially overnight. This enables features like period/fertility prediction (since basal body temperature rises after ovulation) and illness detection. In fact, one user reported that Oura warned of an elevated temperature and breathing rate early in the day before they “spiked a fever that evening,” allowing early rest. In practice, the ring logs nightly temperature deviations: if it’s consistently higher than your baseline, Oura may flag that you’re getting sick or ovulating. (Note: the ring is not a medical device, but the temperature trend can be a helpful early warning.) The temperature data also contributes to the Readiness Score. Users say these insights are intuitive – one noted the ring “reassures me I don’t probably have sleep apnea” by giving an average SpO₂ and interpretation.
6. Battery and Charging
Oura Ring 4 offers excellent battery life. The company advertises up to 8 days per charge (slightly higher than the Gen3’s 7-day spec), but actual runtime depends on usage and ring size. In real-world tests, a size-10 ring lasted around 5½–6 days of continuous wear and workouts. Wired’s reviewer similarly noted being on “day 4 of wearing Oura 4” with still “2–3 days of battery left”. By comparison, most Fitbits last 5–7 days, and Apple Watches only 1–2 days. A handy feature: you can power the ring back up to full in about an hour using the included puck charger. This is much faster than charging a watch, and the ring holds a charge even with all sensors active. The Oura 4’s charging puck is compact and corded, but note it is not backward-compatible with Gen3 rings.
7. Companion App and Data Presentation
The Oura mobile app (iOS/Android) has been redesigned for Gen4. Data is organized into Today, Vitals, and Health tabs, with interactive timelines and tags. A timeline view of each day shows your activity, sleep, and readiness in context, and you can add tags (e.g. “traveling” or “workout”) for pattern tracking. Sleep and readiness scores are summarized front-and-center. The app displays detailed graphs (sleep stages, nightly SpO₂ and temperature, daily heart-rate charts, etc.), although one user noted some raw values (e.g. per-minute SpO₂) aren’t directly shown – instead, Oura interprets them into trends and messages. A notable new feature is Oura Advisor, an AI-powered assistant in the app. You can ask it questions about your data or health goals, and it will provide personalized tips and explanations. Oura lets you customize the Advisor’s tone (supportive vs. direct) and how often it checks in. The app also includes built-in guided meditations and content to help with sleep and recovery. Overall, the UX is praised as intuitive: one user said, “the app is super user-friendly and everything [in it] comes with explanations”. Like Gen3, Oura syncs to Apple Health/Google Fit and has integrations with many services (over 600, including fertility and meditation apps).
8. Subscription Model and Pricing
The Oura Ring 4 starts at $349 (USD) – about $50 more than Gen3 did. All models (stealth, silver, gold, etc.) follow this pricing, with premium finishes (e.g. matte black DLC or gold) costing extra. However, a key consideration is Oura’s membership subscription. New buyers get a 30-day free trial, after which an Oura membership is required for most features (currently $5.99/month or $71.99/year). Non-paying users only see the daily Sleep, Readiness and Activity scores and basic educational content. A membership unlocks the full history, advanced insights (temperature trends, HRV, menstrual/fertility, meal timing, etc.) and the new AI Advisor. Many reviewers criticize this as a downside. TechRadar notes that the subscription “acts as a paywall” to nearly all data beyond the core scores and hurts the value proposition. (For comparison, Fitbit and Whoop also charge for their premium analytics, while Apple Watch includes all features without an extra fee.) In sum, you must factor the ongoing $6/month subscription into the cost of ownership – otherwise you get only limited use of the ring’s capabilities.
9. Accuracy and Comparative Performance
Independent and expert tests confirm the Oura Ring 4 is extremely accurate for sleep and rest metrics. As noted, a scientific study found the Oura Gen3 outperformed Apple Watch and Fitbit Sense in sleep-stage accuracy (5–10% higher overall) and had the highest sensitivity for deep sleep and waking events. In practical use, reviewers say Gen4’s improved sensors make it even more reliable. For example, Oura 4 detected a night of insomnia that a Garmin watch missed. TechRadar deemed its sleep tracking “pretty much the gold standard”. For daytime activity, Oura does well for general fitness: its heart-rate and calorie estimates closely matched those from wrist-based devices during runs and hikes. However, some experts caution that any finger-based tracker has limits: exercise metrics (pace, cadence, specific workout data) will never match a dedicated watch or GPS device. In other words, Oura excels at recovery and wellness metrics (sleep, HRV, daily readiness) but is less detailed for sports performance. Users have reported issues with fit or durability: notably, several reviews mention that a loose ring may lose contact and skip data, so proper sizing (using the Oura sizing kit) is crucial. TechRadar also warns that the polished titanium finish can scratch if banged against hard surfaces. These are worth keeping in mind if you plan intense workouts.
10. Comparison to Previous Model (Gen3)
Compared to the Oura Ring Gen3, the Gen4 offers a cleaner design and notably improved sensing. All Gen4 models are fully titanium (inside and out), whereas Gen3’s interior had epoxy under the sensors. The new ring is slightly thinner (2.88 mm vs ~2.9 mm) and lighter, and the dimples have been eliminated for a smooth interior. There are more size options (4–15 vs 6–13) and a new design selection (six finishes, including a new polished silver). Critically, Oura reports that Gen4’s sensor gains yield higher accuracy: they claim ~30% better SpO₂ accuracy and 15% better breathing-disturbance detection than Gen3. Battery life is also modestly improved: where Gen3 was rated ~7 days, Gen4 can reach ~8 days (the added capacity depends on ring size). The trade-off is cost: the Gen4 launched $50 above Gen3’s price, and uses a new USB-C charging cable (no backward dock compatibility). Overall, Gen4 fixes many Gen3 complaints (e.g. fit, comfort, accuracy), but retains the same subscription model and adds new software features (AI Advisor, enhanced cycle and stress insights) that Gen3 owners can also access via updates.
12. Comparison to Other Wearables
| Feature | Oura Ring 4 | WHOOP 4.0 | Fitbit Sense 2 | Apple Watch Series 9 |
|---|---|---|---|---|
| Form | Finger ring (titanium) | Wrist strap device | Wristband/watch (touchscreen) | Smartwatch (touchscreen) |
| Display | None | None | Yes (OLED) | Yes (OLED) |
| Battery | ~5–7 days (up to 8) | ~4–5 days (with clip charger) | ~5–7 days | ~18–36 hours |
| Sensors | HR, HRV, SpO₂, skin temp, accel, gyroscope, body temp | HR, HRV, SpO₂, skin temp, accel | HR, HRV, SpO₂, ECG, skin temp (Fitbit Sense) | HR, HRV, SpO₂, ECG, accel, gyroscope |
| Swim/Water | Yes, 100 m | Yes, 10 m | Yes, 50 m (waterproof) | Yes, 50 m (waterproof) |
| Sleep tracking | Detailed stages + sleep score | Detailed (sleep and recovery focus) | Detailed + sleep score | Basic sleep tracking (no score) |
| Activity tracking | Steps, basic activity, auto workout detection (limited) | “Strain” focus (no step count) | Steps, distance, workouts (built-in GPS) | Steps, workouts, GPS |
| Recovery/Readiness | Yes (Readiness Score) | Yes (Recovery metric) | Sleep & Active Zone metrics (with Premium) | No (provides rings, no composite score) |
| Connectivity | iOS/Android app | iOS/Android app | iOS/Android app | iPhone (iOS only) |
| Subscription | Required for full features ($5.99/mo) | Required ($30+/mo) | Optional for premium insights | None |
| Cost (base) | $349+ | $299 (device) + membership | ~$299 | ~$399 |
This table illustrates that Oura Ring 4 is a screenless, long-battery wearable focused on health monitoring. Unlike WHOOP and Fitbit, it has no strap or screen, and unlike Apple, it doesn’t handle calls or apps. Its strengths are multi-day battery, sleep/readiness scoring, and a very compact form. In contrast, Apple Watch excels at notifications, apps, GPS workouts, and medical features (ECG), but must be charged daily and offers limited sleep data. Fitbit devices (like Sense 2 or Pixel Watch) cover both fitness and sleep, with some models having ECG and GPS, but generally stay on the wrist. WHOOP is similar to Oura in that it’s wearable day/night, tracks HR/HRV/SpO₂ and sleep, and charges every few days – but WHOOP lacks any display or step count, and has a much higher monthly fee.
13. Expert Reviews and User Feedback
Tech publications unanimously praise Oura 4’s hardware and sleep accuracy. TechRadar calls it “almost the perfect fitness tracker” with a “superb” build and 5/5 performance score, though lamenting the “ongoing, necessary subscription”. Wired (9/10) highlights the new sensors and app features: “more accurate, useful, and easier to wear”. Wareable notes both Oura and Fitbit have excellent sleep tracking, but says Oura offers more granular data and a unique Readiness metric. The consensus: the Oura Ring 4 is highly accurate for sleep/recovery (often exceeding Apple/Fitbit) and comfortable for 24/7 wear, but it costs more upfront and requires a subscription.
Actual user reviews echo this. On Amazon, many customers report that the Ring “lives up to expectations” for sleep insights and recovery coaching. One verified buyer said the app is “super user-friendly” and the ring even predicted a fever days in advance. Another noted it gave “great insight into health patterns” (e.g., tracking stress levels on cancer-treatment days). Several users point out that the sizing kit is essential – a too-loose ring can skip heart-rate readings. Some user concerns have emerged: reviewers caution that the metallic finish can scratch if knocked, and threads on Reddit mention rare instances of charging failures or breakage (though official warranty service is available). Overall, though, the Amazon average is ~4.2/5 with many 5-star reviews praising its comfort and data insights.
Pros and Cons
- Pros:
- Extremely detailed sleep and recovery tracking (often outperforming smartwatches).
- Lightweight, low-profile design (no screen bumps) that’s comfortable 24/7.
- Multi-day battery (5–7+ days), fast 1-hour charging.
- Always-on HR, HRV, SpO₂, and temperature sensing. Detects readiness, stress, menstrual cycles, etc.
- Waterproof and discreet (good for sleep, swimming, etc.).
- Companion app is informative, with new AI Advisor, tags, and meditations.
- Cons:
- Requires an ongoing monthly subscription ($5.99) for most features.
- Premium price ($349+) for the ring itself, with no one-time alternative.
- Lacks a display/GPS, so no real-time workout feedback – not ideal for tracking pace or navigation.
- Sizing can be tricky (the ring must fit snugly).
- The polished titanium can be scratched with rough use.
- Does not replace a smartwatch for notifications, calls, or third-party apps.
In summary, the Oura Ring 4 is a best-in-class wearable for sleep, readiness, and holistic health tracking, offering more detailed and accurate data than its predecessors and most competitors. Its strengths are comfort, battery life, and insight depth. The trade-offs are price and the subscription requirement, and limited “active” tracking features. For users focused on recovery and wellness (and willing to pay for them), it delivers exceptional performance; for those needing full smartwatch or athletic training features, a wrist device might be more appropriate.