Whoop · Fitness Band
Whoop 4.0
The previous Whoop. Replaced by the 5.0 with longer battery and Healthspan.
DiscontinuedWhoop no longer sells it new, so the price is its last list price.See current models
$19.92/moWhoop →
Key specs
- Battery life
- 5 days
- Charging
- Hot-swap (no downtime)
- Weight
- 30g
- Display
- No screen
- Water resistance
- 1 ATM (10m)
- Phone
- iPhone or Android
- Sensors
- Optical heart rate, SpO₂, Skin temperature, Accelerometer, Multi-path PPG
The Whoop 4.0 (2021) brought continuous HR + SpO₂ + skin-temp to the band format. Replaced in 2025 by the Whoop 5 with double the battery life and Healthspan / longevity scores. No longer sold new.
Strengths
- Continuous HR sampling
- Battery pack swaps in place
- Whoop Coach AI included
Tradeoffs
- Replaced by Whoop 5
- No longevity / Healthspan tools
- Subscription required — $239/yr or $30 month-to-month
Full specs
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Common questions
- How much does the Whoop 4.0 cost?
- The Whoop 4.0 has no separate hardware price — it comes with the Whoop membership at $19.92/mo.
- Does the Whoop 4.0 require a subscription?
- Yes. The Whoop 4.0 needs an active Whoop membership at $19.92/month — without it the device stops reporting your data.
- How long does the Whoop 4.0 battery last?
- About 5 days of typical use per charge. Heavy GPS use, an always-on display, and continuous sensing all pull that number down.
- How much does the Whoop 4.0 weigh?
- The Whoop 4.0 weighs 30 g.
- Is the Whoop 4.0 waterproof?
- The Whoop 4.0 is rated 1 ATM (10m). Treat that as protection against rain, sweat, and handwashing rather than a swimming rating.
- Does the Whoop 4.0 work with iPhone and Android?
- It pairs with both iPhone and Android.
- Is the Whoop 4.0 still worth buying?
- The Whoop 4.0 came out in 2021 and Whoop has discontinued it, so new stock is limited and prices vary. Check it against the current fitness band lineup before buying.