WHOOP
WHOOP 4.0
—
Released 2021-10
Best Fitness Trackers · head-to-head
WHOOP 4.0 vs Ultrahuman Ring AIR
A sourced, side-by-side comparison. Ultrahuman Ring AIR is cheaper at $349. Every spec and price links to its source.
Ultrahuman
Ultrahuman Ring AIR
$349
Released 2023-09
Full spec sheet
✓ marks the stronger figure where "more" — or "less", for price and weight — is unambiguously better.
| Spec | WHOOP 4.0 | Ultrahuman Ring AIR |
|---|---|---|
| US price | — | $349 |
| Brand | WHOOP | Ultrahuman |
| Released | 2021-10 | 2023-09 |
| Form factor | band | ring |
| Display | — | — |
| Battery days | 5 | 6 |
| Gps | No | No |
| Spo2 | Yes | Yes |
| Ecg | No | No |
| Subscription required | Yes | No |
| Water resistance (m) | 10 | 100 |
| Release | 2021 | 2023 |
Sources — WHOOP 4.0: dcrainmaker.com (verified 2026-06-15). Ultrahuman Ring AIR: androidcentral.com (verified 2026-06-15).
What's the difference between the WHOOP 4.0 and Ultrahuman Ring AIR?
Where the two actually differ on the specs we track (4 of 8). Matching specs are omitted.
- Form factor: WHOOP 4.0 band vs Ultrahuman Ring AIR ring
- Battery days: WHOOP 4.0 5 vs Ultrahuman Ring AIR 6
- Subscription required: WHOOP 4.0 true vs Ultrahuman Ring AIR false
- Water resistance (m): WHOOP 4.0 10 vs Ultrahuman Ring AIR 100
What reviewers say
Sourced tester consensus for each — the "what people who used it think" layer, not just specs.
WHOOP 4.0
Across 3 testing outlets, the Whoop 4.0 earns a consistently positive verdict, with GearJunkie scoring it 8.0/10. Reviewers converge on its accuracy for sleep, strain, and recovery tracking and its tangible impact on users' daily habits, while the recurring subscription cost (up to $30/month, or $239/year) is the main friction point raised. Battery life is reported consistently at around 4 to 5 days across sources. (3 sourced reviews, 3 lab-tested.)
Praised: Accurate sleep, recovery, and strain tracking (validated against gold-standard measures in one study, corroborated by consistency checks and accurate strain/recovery predictions); Meaningful, positive impact on users' lifestyle and habits; Consistent readings when compared against other wearables.
Flagged: Ongoing subscription cost is a sticking point for some users/reviewers.
Ultrahuman Ring AIR
Two whitelisted testers (TechRadar, Tom's Guide) wore the Ring Air for a month and 60 days respectively, both benchmarking it against Apple Watch and Oura. Both praise its featherweight comfort, detailed data and no subscription; both flag easy scratching. Verdicts converge: a capable, data-heavy ring for enthusiasts. No RTINGS lab data exists. (2 sourced reviews, 2 lab-tested.)
Praised: Extremely lightweight (2.4-3.6g) and comfortable, even for sleep; Heart-rate/steps/sleep data tracks closely with Apple Watch and Oura references; No mandatory subscription to view your data.
Flagged: Scratches easily, especially the matte black finish, within weeks; Overwhelming volume of data; app less user-friendly than Oura; No screen means you must open the app for everything.