Fitbit confirms it has begun the rollout of blood oxygen monitoring feature to some of its wearables
Fitbit's devices from recent years have blood oxygen monitoring (SpO2) hardware, but they haven't used it — until now. Users on Reddit and elsewhere have noticed that their Versa …
Context & Ripple Effects
Fitbit has been shipping SpO2 sensors in its recent wearables for years while leaving them dormant; this rollout finally switches that hardware on through a software update, starting with users who spotted the feature appearing on their Versa devices. It follows the playbook of earlier app-side additions like period tracking arriving on Versa and Ionic — new capability delivered to hardware already on wrists.
The catch is fragmentation: Fitbit had already declared OS 5.0 exclusive to the Versa 3 and Sense, so which devices get blood oxygen readings depends heavily on firmware generation — a split that deepened when OS 5.1 made blood oxygen readings automatic on the newer models only.
First-order effects
- Owners of recent Versa-generation devices gain sleep-oriented blood oxygen data with no purchase required, converting idle sensor hardware into a live feature overnight.
- Fitbit gets a differentiator for its installed base at near-zero marginal cost, since the rollout is software rather than new SKUs.
Second-order effects
- Feature parity pressure shifts to Apple and other rivals, whose own SpO2 implementations show how contested the metric becomes — Apple later had to ship a redesigned blood oxygen feature to route around an ITC import ban.
- Fragmented firmware support pushes buyers toward the newest Sense/Versa 3 tier, reinforcing the upgrade funnel Fitbit built when it cut older devices like the Versa 2 off from OS 5.0.
Third-order effects
- Wearable competition increasingly runs on unlocking sensors already in the field plus regulatory clearances — the path Fitbit later took with FDA clearance for passive AFib detection — rather than on hardware specs alone.
- If dormant-sensor activation becomes standard practice, health-feature rollouts turn into a software-update cadence problem, where firmware eligibility, not sensor presence, decides which users get clinical-grade signals.
The trend: Smartwatch makers are shipping biosensors ahead of their software and regulatory readiness, then activating features post-purchase — making firmware eligibility, not hardware, the real dividing line between device generations.