Oura Ring 4 vs Oura Ring 3: What's Changed and Which Should You Get?

Oura released the fourth generation of its smart ring in late 2024, bringing a fresh design and upgraded sensors. But with the Oura Ring 3 (Heritage and Horizon) still in use by millions of people, it's worth asking: what actually changed, and is it worth upgrading?

Here's a straightforward comparison of everything that matters.

Looking at Oura's newest generation? Read our Oura Ring 5 vs Oura Ring 4 comparison.

Design and Comfort

The most obvious change with the Oura Ring 4 is the design. Oura ditched the inner bump that housed the sensors in previous generations. The Ring 4 has a completely smooth, concave inner surface — making it noticeably more comfortable, especially during sleep.

The Ring 3 came in two styles — Heritage (flat top) and Horizon (fully round). The Ring 4 drops the Heritage style entirely and keeps only the rounded design, similar to Horizon.

Both generations are made from titanium, but the Ring 4 is slightly thinner and lighter than the Ring 3 Horizon. If comfort was your main complaint with the Ring 3, the fourth generation is a significant improvement.

Sensors and Accuracy

Oura Ring 4 uses a completely redesigned sensor layout. Instead of the three raised LED bumps on the Ring 3, the Ring 4 spreads its sensors across the entire inner surface with a new "Smart Sensing" platform. It has more LEDs and photodiodes, which allows it to collect signals from a wider area of your finger.

In practice, this means:

• Heart rate and HRV tracking is more accurate, with better signal quality during movement
• SpO2 (blood oxygen) readings are more reliable and run throughout the night
• Temperature sensing now uses multiple pathways across the ring instead of a single sensor spot
• Automatic Activity Detection benefits from improved accelerometer data

The Ring 3 still tracks all of these metrics and remains accurate for most users — the Ring 4 just refines the quality of each signal.

Battery Life

Oura claims up to 8 days of battery life for the Ring 4, compared to roughly 4–7 days for the Ring 3 (depending on size and usage). Real-world results vary, but most Ring 4 users report consistently longer battery life than the previous generation.

Both rings charge on a proprietary charger. Note that the Ring 4 uses a different charger than the Ring 3 — they are not interchangeable.

Sizing and Fit

Oura changed its sizing system for the Ring 4. The new sizes don't map one-to-one with Ring 3 sizes, so if you're upgrading, you'll likely need to use a new sizing kit.

Ring 4 sizes range from 4 to 15, while Ring 3 went from 6 to 13. The expanded range means the Ring 4 fits more people, including those with smaller fingers.

Features and Software

Both rings run on the same Oura app and share the same core feature set, including:

• Readiness, Sleep, and Activity scores
• Heart rate and HRV monitoring
• Body temperature trends
• Cycle tracking
• Cardio Capacity (VO2 Max estimate)
• Sleep staging (Awake, Light, Deep, REM)

Some newer software features — like improved daytime heart rate tracking — work better on the Ring 4 due to the upgraded sensors, but Oura hasn't locked any major features to Ring 4 only. The Ring 3 continues to receive app updates.

Subscription

Both the Oura Ring 3 and Ring 4 require the Oura Membership ($5.99/month) to access detailed insights, trends, and scores beyond the basics. The Ring 4 no longer includes a free trial period for new members — something to keep in mind if you're buying for the first time.

Price

The Oura Ring 4 starts at $349, the same launch price as the Ring 3 Horizon. Since the Ring 3 has been discontinued for new purchases, you'll mostly find it on the secondhand market at lower prices.

Which One Should You Get?

Get the Ring 4 if:

• You're buying your first Oura Ring
• You want the most comfortable and accurate ring available
• Battery life matters to you
• You found the Ring 3's inner bump uncomfortable

Stick with the Ring 3 if:

• Your current ring is working well and tracking accurately
• You prefer the Heritage (flat-top) design
• You don't want to buy a new charger and go through re-sizing

For most new buyers, the Ring 4 is the clear choice. For current Ring 3 owners, the upgrade is nice-to-have rather than essential — your ring still does its job well.

Track Both Rings with Ring Widget

No matter which generation you're wearing, Ring Widget works with both the Oura Ring 3 and Oura Ring 4. Add your Readiness, Sleep, Activity scores, and more directly to your iPhone home screen — no need to open the Oura app every time you want to check in.

Ring Widget pulls data from the Oura API, so it works seamlessly regardless of your ring hardware. Whether you're rocking a Ring 3 Heritage or the latest Ring 4, your metrics are one glance away.

Sources

• Oura Ring 4 — Official Product Page — Oura
• Introducing Oura Ring 4 — Oura Blog
• Oura Ring Generation 3 — Oura Help Center