Fitbit dark theme arrives alongside upcoming Gemini-powered coach
Fitbit app version 4.50 is rolling out to Android and iOS users. This update introduces a long-awaited dark mode and lays the groundwork for the Gemini-powered personal health coach coming later this year.
Dark mode arrives as part of Fitbit app 4.50
Fitbit is bringing some visual comfort to its app experience with the introduction of a dark theme. While users have been asking for it for a long time, it has only now arrived with version 4.50 of the app, available on both Android and iOS. The release follows the Made by Google 2025 event, where the company also previewed its upcoming AI health coach.
The dark mode toggle sits in the app settings menu. If your phone is already in dark mode, the Fitbit app should match your system preference. You can also enable or disable it manually if you prefer. It’s a separate design element from the broader Material 3 Expressive redesign, which hasn’t yet rolled out in full.
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According to Fitbit, the new theme has several benefits beyond simply changing the color scheme. It’s designed to reduce eye strain, especially at night, by emitting less blue light. Users on devices with OLED displays should also see battery savings, since darker pixels consume less power. The contrast between text and background is sharper, which may improve readability for some users. And the app now carries a more modern, subdued look.
The rollout is not 100 percent complete, though. Fitbit notes that a few elements of the app may not fully support the dark theme just yet. Those will likely be addressed in future updates.
AI-powered health coach preview coming in October
The dark mode update comes as a warm-up for what Fitbit sees as a major shift in how the app delivers health and wellness insights. A Gemini-powered personal health coach is set to debut in preview form later this year.
The feature will be exclusive to Fitbit Premium subscribers using the latest Fitbit trackers, smartwatches and Pixel Watches.
Google says the new coach combines fitness planning, sleep guidance and wellness tracking into a single adaptive experience. It will take into account real-time metrics from your devices, plus any additional data pulled from Health Connect or Apple HealthKit. Over time, the coach learns your preferences and habits, offering more contextually relevant advice.
Workout suggestions will be dynamic, adjusting based on readiness, recovery and daily conditions. Sleep coaching will be driven by a new algorithm that looks at quality and patterns across the week, offering adjustments like extended rest after hard training days. You’ll also be able to ask the coach direct questions about your routine, recovery or goals.
This all sits inside a redesigned Fitbit app that’s being rebuilt around coaching and insights. Alongside the AI layer, Fitbit says it has improved navigation, syncing and data presentation. The idea is to make insights easier to find and understand, without needing to dig through graphs and menus.
Science-backed advice and user input
Fitbit’s AI push includes some high-profile partnerships. The company has worked with Stephen Curry’s performance team and assembled a consumer health advisory panel of researchers and medical professionals. A research paper on its Personal Health LLM was recently published in Nature Medicine, underlining Fitbit’s aim to position the new coach as evidence-based rather than just algorithmic.
For now, this new AI feature is not yet live. The preview will roll out in October, and Premium users in the US can already sign up for early access. Fitbit is presenting it as a collaborative process, where user feedback will shape how the coach evolves before wider release.
The 4.50 app update is a step in that direction. While dark mode might seem like a cosmetic change, it’s also a sign that Fitbit is refreshing the broader app environment ahead of deeper AI integration. Expect more updates in the coming months as the new coaching experience takes shape.
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