Fitbit rolls out OS 5.1 for Sense and Versa 3 smartwatches, with Google Assistant, voice-to-text, phone calls, and automatic blood oxygen readings
Ben Schoon / 9to5Google :
Context & Ripple Effects
Fitbit is filling out the software promise made at the launch of the $330 Sense and $230 Versa 3: OS 5.1 delivers the Google Assistant integration previewed then, plus on-watch calls and voice-to-text replies. It follows an unusually hard generational cut — OS 5.0 was built exclusively for the new two watches, leaving even last year's Versa 2 behind.
The blood oxygen piece closes a loop from earlier in 2020, when Fitbit began rolling out manual SpO2 readings to some wearables; making them automatic moves the feature from a spot-check to background sensing.
First-order effects
- Sense and Versa 3 owners gain Assistant queries, spoken replies to messages, and Bluetooth calling on the wrist — the headline gaps versus rivals at launch are now closed for current-generation buyers only.
- Versa 2 and older owners are confirmed second-class: with OS 5.x locked to the new hardware, their upgrade path runs through Fitbit's checkout page, not a firmware update.
Second-order effects
- Google Assistant becoming a Fitbit selling point deepens the companies' software entanglement ahead of their pending combination, echoing how Google used an Assistant feed to differentiate Wear OS back in 2018.
- Competing sub-$300 smartwatches now face a bundle of health sensors plus a mainstream voice assistant at $230–$330, pressuring rivals to match either the assistant or the sensor suite rather than one alone.
Third-order effects
- If flagship-only OS releases become Fitbit's norm, its installed base fragments by generation each cycle — a trade-off that boosts new-unit sales but erodes the loyalty of the long-tail users who made the brand's name.
- Automatic background SpO2 points toward passive, always-on health sensing as the default, turning smartwatch value from notifications toward continuous biometric data — the direction later devices like the Inspire 3 and Sense 2 generation pushed further.
The trend: Fitbit's watch platform is converging with Google's assistant stack while segmenting its own lineup by hardware generation, trading installed-base unity for per-cycle upgrade pressure.