Oura Ring 4 Review: What's New and Is the Upgrade Worth It?

The Oura Ring has been the quiet achiever of the health wearable market. While Whoop and Apple Watch compete for your wrist, Oura has built a loyal following among people who want accurate health data without a screen, notifications, or anything that looks like it belongs in a meeting notification. It is a ring. You wear it. It tracks your sleep, recovery, and activity. It does not buzz, beep, or display your work emails.

The Oura Ring 4 (Generation 4) represents the most significant hardware update since the original ring. New sensors, a redesigned form factor, improved algorithms, and expanded daytime tracking. We have been wearing it for 12 weeks alongside a Ring 3 and a Whoop 4.0 to give you an honest assessment of what changed, what improved, and whether the upgrade is worth it.

What Is New in the Ring 4

Redesigned Sensor Array

The Ring 4 uses a new multi-wavelength sensor system with additional LEDs compared to the Ring 3. The Ring 3 had green and infrared LEDs for heart rate and SpO2. The Ring 4 adds red LEDs and repositions the sensor array for better skin contact across a wider range of finger sizes.

In practice, this means two things: heart rate accuracy has improved (especially during movement), and the ring now captures usable data from more finger positions. The Ring 3 was occasionally finicky about ring placement — it needed to be on the index finger or middle finger for best results. The Ring 4 is more forgiving.

Daytime Heart Rate and HRV

This is the headline feature. The Ring 3 primarily tracked health metrics during sleep and delivered a morning "Readiness Score" based on overnight data. The Ring 4 adds continuous daytime heart rate monitoring and daytime HRV (heart rate variability) sampling throughout the day.

Why this matters: HRV is one of the best proxies for autonomic nervous system balance — essentially how recovered and resilient your body is. Overnight HRV is useful, but it only tells you about one window of time. Daytime HRV shows how your body responds to stress, meals, exercise, caffeine, and other real-world inputs. It turns HRV from a morning score into a dynamic, actionable metric.

The daytime heart rate tracking is sampled every five minutes (not continuous like Apple Watch). This is a deliberate design decision to preserve battery life while still providing useful trend data. You can see your heart rate throughout the day, spot stress responses, and correlate heart rate patterns with activities and habits.

Improved Sleep Staging

Oura has always been strong on sleep tracking — multiple independent studies have rated it as the most accurate consumer sleep tracker, comparable to clinical-grade polysomnography in some metrics. The Ring 4 improves sleep staging accuracy further, particularly in distinguishing between light sleep (N1/N2) and deep sleep (N3).

In our testing, the Ring 4's sleep staging aligned more consistently with perceived sleep quality than the Ring 3. Nights that felt restless showed more light sleep and wake periods. Nights that felt restorative showed more deep sleep and REM. The Ring 3 occasionally missed brief wake-ups; the Ring 4 catches them more reliably.

Slimmer Profile

The Ring 4 is approximately 0.5mm thinner than the Ring 3 at its thickest point (the sensor bump on the inside of the band). This is a subtle but noticeable improvement. The Ring 3 had a small raised section on the palm side that you could feel when gripping something tightly — a barbell, a steering wheel, a golf club. The Ring 4 reduces this enough that we forgot we were wearing it during workouts.

Battery Life

Oura claims 7 days of battery life for the Ring 4. In our testing, we averaged 5.5–6 days with daytime heart rate enabled and all features active. With daytime HR disabled (reverting to sleep-only tracking), we got 7+ days consistently.

The Ring 3 averaged 5–7 days in our long-term use. So battery life is roughly equivalent, despite the Ring 4 doing significantly more work with daytime tracking. The improved power efficiency of the new sensor array keeps things in check.

Charging takes about 60–80 minutes from empty. The charger is the same dock-style design as the Ring 3, though it is a different charger (not cross-compatible).

What Has Not Changed

The Subscription Model

The Oura Ring 4 still requires a $5.99/month Oura Membership to access most features beyond basic sleep tracking. Without the subscription, you get a Sleep Score, a Readiness Score, and basic sleep data. With the subscription, you get detailed sleep staging, HRV trends, temperature tracking, blood oxygen, daytime HR, guided meditations, and the full Oura experience.

This remains the most divisive aspect of Oura. You pay $299–$549 for the hardware, then $72/year indefinitely for the software that makes it useful. Whoop charges $30/month but includes the hardware for free (with a 12-month commitment). Apple Watch has no subscription. Every model has tradeoffs.

Our take: the subscription is worth it if you actively use the data. If you just glance at your Sleep Score each morning and move on, you are paying $72/year for a number you could estimate yourself. If you track HRV trends, optimize your sleep environment, and use the data to make training and recovery decisions, it pays for itself in better health outcomes.

No Display, No Notifications

The Ring 4 is still just a ring. No screen, no haptic buzzes (it does have a gentle vibration alarm for alarms, but no notification forwarding), no Bluetooth calling, no music controls. If you want those things, wear an Apple Watch. Oura's entire value proposition is that it tracks your health without any of the distractions of a smartwatch.

Sizing and Fit

Oura still ships a free sizing kit before you order. This is important — ring sizes vary between fingers and even throughout the day (fingers swell in heat and shrink in cold). Order the sizing kit, wear the sample ring for 24 hours on your preferred finger, and order accordingly. Getting the size wrong results in either uncomfortable tightness or inaccurate readings from a loose sensor.

Ring 4 vs Ring 3: Should You Upgrade?

This is the question most existing Oura users are asking. Here is our honest assessment:

Upgrade if:

• Daytime HRV matters to you. If you want HRV as a dynamic, all-day metric rather than just a morning number, the Ring 4 is the only way to get it from Oura. This is the single biggest reason to upgrade.
• Your Ring 3 has accuracy issues. Some Ring 3 users — particularly those with smaller fingers or who wear the ring on non-optimal fingers — experience inconsistent readings. The Ring 4's improved sensor array addresses this.
• You want better sleep staging. If you are serious about sleep optimization and use the detailed staging data, the Ring 4's improvements are meaningful.
• Your Ring 3 is 2+ years old. Battery degradation is real. If your Ring 3 no longer lasts 4+ days, upgrading makes more sense than dealing with frequent charging.

Do not upgrade if:

• You are happy with Ring 3 sleep tracking. If overnight data is all you need and your Ring 3 is accurate and holds charge, the Ring 4 improvements are incremental for your use case.
• You are on a budget. The Ring 4 is $299–$549 plus $72/year subscription. If your Ring 3 is working fine, that money is better spent elsewhere.
• You want continuous heart rate. The Ring 4 samples every five minutes, not continuously. If you need beat-by-beat heart rate data during workouts, a wrist-based wearable (Apple Watch, Whoop, Garmin) is still more appropriate.

Ring 4 vs Whoop 4.0 vs Apple Watch

Oura Ring 4 is the best sleep tracker. Its ring form factor provides more consistent skin contact during sleep than any wrist device, and the sleep staging accuracy reflects this. It is the least intrusive wearable — no screen, no notifications, no visible tech. Best for people who prioritize sleep and recovery data above all else.

Whoop 4.0 is the best recovery and strain tracker. Its continuous heart rate monitoring and strain scoring algorithm are excellent for athletes who want to quantify training load and recovery. The subscription-only model ($30/month, hardware included) is expensive but eliminates the upfront cost. Best for serious athletes.

Apple Watch is the best smartwatch that also tracks health. It does everything — notifications, apps, workouts, health tracking — but none of the health metrics are as accurate as dedicated devices. Sleep tracking in particular is weaker than both Oura and Whoop. Best for people who want a smartwatch first and health tracker second.

The 12-Week Verdict

After 12 weeks of daily wear, the Oura Ring 4 has become our primary sleep and recovery tracker. The daytime HRV feature alone justifies the hardware upgrade for anyone serious about health optimization. Seeing how HRV responds to a stressful meeting, a heavy lunch, an afternoon coffee, or a hard workout provides actionable data that overnight-only tracking cannot match.

The sleep tracking remains best-in-class. The form factor is more comfortable than the Ring 3. The battery life holds up despite expanded capabilities. And the absence of a screen continues to be, paradoxically, one of its best features — it gives you data without giving you another reason to look at a device.

The subscription model is the asterisk. It is the price of admission to a product that is already premium-priced. We accept it because the data quality justifies the cost. But we understand the frustration of paying rent on hardware you already own.

Key Takeaways

• The Oura Ring 4's daytime HRV and improved sensors are the most meaningful upgrades over the Ring 3
• Sleep tracking accuracy is the best in any consumer wearable, and the Ring 4 improves on the Ring 3's already strong performance
• Battery life is 5.5–6 days with all features active — roughly equivalent to the Ring 3 despite doing more
• The $5.99/month subscription is still required for full functionality
• Upgrade from Ring 3 if daytime HRV matters to you or your Ring 3 has accuracy or battery issues
• Do not upgrade if your Ring 3 is working well and overnight data meets your needs
• For sleep tracking specifically, nothing on the market beats the Oura Ring

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