Device comparisons
Oura Ring Gen 3 vs Gen 4: Is the PPG Sensor Upgrade Worth It?
Oura Ring 4 replaced Gen3 in 2024 with what Oura calls Smart Sensing: an 18-path PPG layout using green and infrared light for heart rate and red and infrared for SpO2. Oura quotes up to 7 days of battery for Gen3 and typically 5–8 days for Ring 4. Both are water resistant to 100 m. No independent study has compared Gen3 and Ring 4 accuracy, so this page does not claim one.
Devices
The photograph is an Oura Ring 4 in silver, standing in for Gen3. A distinct Gen3 product still was not available. Oura Ring 4 in silver: product photograph from Oura.
At a glance
This page does not list head-to-head accuracy numbers, so the scoreboard shows hardware differences only.
| Specification | Oura Ring Gen3 | Oura Ring 4 |
|---|---|---|
| Battery LifeDiffers | Up to 7 days | Typically 5–8 days |
| AvailabilityDiffers | Discontinued | — |
| Optical sensorDiffers | — | 18-path PPG; green/IR for HR, red/IR for SpO2 |
Primary rows only. The study tables further down list more results from the accuracy database.
Hardware specs
| Specification | Oura Ring Gen3 | Oura Ring 4 |
|---|---|---|
| Battery LifeDiffers | Up to 7 days | Typically 5–8 days |
| Water Resistance | 100 m | 100 m |
| AvailabilityDiffers | Discontinued | — |
| Optical sensorDiffers | — | 18-path PPG; green/IR for HR, red/IR for SpO2 |
Hardware only. Study results are not repeated in this table. Differs marks values that are not the same. An em dash means this page did not publish that figure.
Specs verified on October 17, 2026: Oura: Smart Sensing in Oura Ring 4, Oura Support: Oura Ring 4 battery life, Oura Support: general FAQs (battery, water resistance), Oura Support: previous Oura Ring generations, Oura Support: Oura Membership.
Pros and cons
Oura Ring Gen3
Pros
- Up to 7 days battery (Oura)
- Water resistant to 100 m
- Same Oura app and membership features
Cons
- No longer sold by Oura
- Lacks Ring 4's 18-path Smart Sensing layout
Oura Ring 4
Pros
- 18-path PPG Smart Sensing (Oura)
- Typically 5–8 days battery in Oura's testing
- Water resistant to 100 m
Cons
- Blood Oxygen Sensing can shorten battery by up to two days (Oura)
- No published independent accuracy comparison with Gen3
What published studies show
One table per metric. These rows come from the accuracy database and are not repeated as a second card list. From the wearable accuracy database (v1.0.0).
Heart rate during exercise1 study
| Device tested | Result | Reference | Sample | Study |
|---|---|---|---|---|
| Oura Ring Gen3mixed rest/stress/walking | 9–14 bpm (group range)Mean absolute error | ECG chest strap (Zephyr BioHarness / | n = 45, Rest, cognitive stress, steady and intermittent walking in neutral/ | Gielen et al. (2026)Funding not reported |
Overnight heart rate1 study
| Device tested | Result | Reference | Sample | Study |
|---|---|---|---|---|
| Oura Ring Gen3 | 1.67%Mean absolute percentage error | ECG | n = 13, Home, during sleep, 536 nights | Dial et al. (2025)Independent |
| Oura Ring Gen3 | 0.97Lin's concordance correlation | ECG | n = 13, Home, during sleep, 536 nights | Dial et al. (2025)Independent |
| Oura Ring 4 | 1.94%Mean absolute percentage error | ECG | n = 13, Home, during sleep, 536 nights | Dial et al. (2025)Independent |
| Oura Ring 4 | 0.98Lin's concordance correlation | ECG | n = 13, Home, during sleep, 536 nights | Dial et al. (2025)Independent |
HRV (RMSSD)1 study
| Device tested | Result | Reference | Sample | Study |
|---|---|---|---|---|
| Oura Ring Gen3 | 7.15%Mean absolute percentage error | ECG | n = 13, Home, during sleep, 536 nights | Dial et al. (2025)Independent |
| Oura Ring Gen3 | 0.97Lin's concordance correlation | ECG | n = 13, Home, during sleep, 536 nights | Dial et al. (2025)Independent |
| Oura Ring 4 | 5.96%Mean absolute percentage error | ECG | n = 13, Home, during sleep, 536 nights | Dial et al. (2025)Independent |
| Oura Ring 4 | 0.99Lin's concordance correlation | ECG | n = 13, Home, during sleep, 536 nights | Dial et al. (2025)Independent |
Sleep stages (4-stage)3 studies
| Device tested | Result | Reference | Sample | Study |
|---|---|---|---|---|
| Oura Ring Gen3 | 76.0–79.5% (range across stages)Sensitivity | Polysomnography (PSG) | n = 35, Inpatient, 1 night | Robbins et al. (2024)Maker funded |
| Oura Ring Gen3 | Not different from PSG for wake, light, deep or REMStudy finding (no single number) | Polysomnography (PSG) | n = 35, Inpatient, 1 night | Robbins et al. (2024)Maker funded |
| Oura Ring Gen3 (OSSA 2.0) | 75.5% (light) to 90.6% (REM), per-stageEpoch-by-epoch agreement | Polysomnography (PSG) | n = 96, Home ambulatory PSG, up to 3 nights | Svensson et al. (2024)Maker funded |
| Oura Ring Gen3 | κ = 0.35Cohen's kappa | Polysomnography (PSG) | n = 53, Two Korean sleep centres, in-lab PSG | Lee et al. (2023)Independent |
More results (1)
| Device tested | Result | Reference | Sample | Study |
|---|---|---|---|---|
| Oura Ring Gen3 | 54.3%Epoch-by-epoch agreement | Polysomnography (PSG) | n = 53, Two Korean sleep centres, in-lab PSG | Lee et al. (2023)Independent |
Sleep vs wake (2-stage)2 studies
Only maker-funded evidence for Oura Ring Gen3 on this metric.
| Device tested | Result | Reference | Sample | Study |
|---|---|---|---|---|
| Oura Ring Gen3 | ≥ 95%Sensitivity | Polysomnography (PSG) | n = 35, Inpatient, 1 night | Robbins et al. (2024)Maker funded |
| Oura Ring Gen3 (OSSA 2.0) | 91.7–91.8%Epoch-by-epoch agreement | Polysomnography (PSG) | n = 96, Home ambulatory PSG, up to 3 nights | Svensson et al. (2024)Maker funded |
| Oura Ring Gen3 (OSSA 2.0) | 94.4–94.5%Sensitivity | Polysomnography (PSG) | n = 96, Home ambulatory PSG, up to 3 nights | Svensson et al. (2024)Maker funded |
| Oura Ring Gen3 (OSSA 2.0) | 73.0–74.6%Specificity | Polysomnography (PSG) | n = 96, Home ambulatory PSG, up to 3 nights | Svensson et al. (2024)Maker funded |
Verdict
Ring 4 is the current model with Oura's redesigned 18-path sensor; Gen3 owners get the same app features. Oura has not published, and we have not found, an independent study showing how much more accurate Ring 4 is, so the upgrade case rests on hardware and availability rather than proven accuracy gains.
Frequently asked questions
Is Oura Ring 4 significantly more accurate than Gen 3?
No independent head-to-head study exists. Oura describes Ring 4's Smart Sensing as an 18-path PPG design but has not published a Gen3-vs-Ring 4 validation that we could verify.
Which has better battery life?
Oura quotes up to 7 days for Gen3 and typically 5–8 days for Ring 4, with Blood Oxygen Sensing cutting Ring 4 battery by up to two days.
Does Oura need a membership?
Without a membership Oura shows Readiness, Sleep and Activity scores; detailed sleep, 24/7 heart rate and SpO2 require a membership (Oura).
Device research records
Datasets, papers and validation results for the models named on this page.