Zyke Band
Know your body. Keep your data.
The screenless band for sleep, recovery and training. Pay once. Your data stays on your phone.
Closed pre-order in selected EU countries starts in December 2026.5 US and UK follow in 2027.
Design
Made to forget.
No screen, nothing to tap, a soft knit strap. Put it on and get on with your day.
- Design. A soft knit strap and a module with no screen. Wear it on your wrist or upper arm. Five colors at launch, with more colors and materials coming later.1
Jet Black
- Sensors. Heart rate, SpO₂, skin temperature and motion, tracked day and night.
- Battery. Up to 7 days on one charge, worn 24/7.2 Fully recharges in under an hour.
- Water. Pool, shower, rain. Keep it on.3
- Local-First App. All of your data is analyzed and stored on your phone, with no account required. Optionally, access all of your data via your own open source sync server or a direct data export.
No screen
Nothing pulls you out of the moment.
Silent alarm
A soft vibration wakes you, not the room.
No subscription
Full data access with a one-time purchase.
App
Understand yourself.
Every second of your day becomes a few clear answers. How ready you are, how hard you went, what your body is telling you.
Ready
See how ready you are for the day ahead.
Load
Your daily effort from heart rate and movement, with an optimum to aim for.
Sleep
Sleep stages, consistency and a bedtime that fits your morning, combined into one Sleep Score.
Body Snapshot
SpO₂, skin temperature and respiratory rate at night, compared with your own baseline.
Daily Log
Log caffeine, magnesium or a late dinner and see how it shapes your nights.
Performance Insights
See how your training load develops over weeks and months.
See how ready you are for the day ahead.
Your daily effort from heart rate and movement, with an optimum to aim for.
Sleep stages, consistency and a bedtime that fits your morning, combined into one Sleep Score.
SpO₂, skin temperature and respiratory rate at night, compared with your own baseline.
Log caffeine, magnesium or a late dinner and see how it shapes your nights.
See how your training load develops over weeks and months.
Built-in Privacy
Stays with you.
Everything is analyzed and stored on your phone. Nothing leaves it unless you choose to back up or sync.
On-device analysis
Scores, sleep stages and trends are calculated on your phone, even offline.
No account needed
The app works fully without signing up.
Open source sync server
Optional. Host it yourself, connect it in the app and access your data via REST or MCP.
Encrypted backup
Off by default. End-to-end encrypted, hosted in Germany. Free for 3 stored backups.
Specs
Every beat counts.
Continuous heart rate, around the clock. Plus the signals that matter for sleep and recovery.
Heart rate and HRV
Every 1 to 4 seconds, with continuous HRV.
SpO₂
Up to 48 times per day, about every 30 minutes.
Skin temperature
Up to 6 times per hour during sleep, to show trends over days and weeks.
Respiratory rate
Up to 6 times per hour, 144 times per day.
All specsSensors · Battery · Water · Wear · Strap · Storage · Data and privacy · Compatibility · Subscription
Sensors
- Heart rate
- Every 1 to 4 seconds, 24/7
- HRV
- Continuous, up to 8,640 times per day (rolling 10 second windows)
- SpO₂
- Up to 48 times per day (about every 30 minutes), depending on motion during measurement
- Skin temperature
- Up to 6 times per hour during sleep
- Respiratory rate
- Up to 6 times per hour, 144 times per day, depending on motion and signal quality
- Motion
- 3-axis accelerometer, steps
Battery
- Runtime
- Up to 7 days2
Water
- Rating
- Swim-ready3
Storage
- On device
- Up to 3 days of data
Data and privacy
- Storage
- All data lives in a local database on your phone
- Analysis
- Scores, sleep stages and trends are calculated on your phone
- Account
- None required
- Backup
- Optional and off by default. End-to-end encrypted, hosted in Germany. Free for 3 stored full backups (up to once per day)
- Sync and API
- Optional open source sync server (single user) that you host yourself. Access your data via REST or MCP
- Export
- Direct data export
Wear
- Positions
- Wrist or upper arm
Strap
- Sizes
- M (approx. 24 cm / 9.4 in), L (approx. 29 cm / 11.4 in), Biceps (approx. 49 cm / 19.3 in). Limited pre-order edition: M/L (approx. 27 cm / 10.6 in)
Compatibility
- Phones
- iOS 18.4 or later, Android 12 or later
- Subscriptions
- None required for full data access
App Features
- Sleep tracking
- Sleep detection, sleep stage estimation, regularity, efficiency and sleep stress, with a daily Sleep Score from 0.0 to 10.0.
- Ready Score
- Your daily readiness from 0.0 to 10.0, based on your overnight signals.
- Body Load
- How much load you put on your body. Based on cardio load, motion load and TRIMP.
- Stress Level
- Continuous, up to 288 times per day
- Body Snapshot
- Your nightly biometrics compared to your personal baseline
- Activity tracking
- Live tracking with your phone's GPS and audio cues. Activities can also be added afterward.
- Daily Log
- Log your mood, how your body feels and your daily habits. Create your own log types right away.
- Performance Insights
- Shows whether you are on track to reach your activity goals.
Yours. For good.
The full experience is included. Every feature you get at launch stays free, forever.
“We started Zyke because the data from your body should belong to you. So we built a band you forget you're wearing and an app that does the thinking on your phone. Thanks for being here early.”
15,000+
on the waitlist
- r/zykeband (opens in a new tab)
community
ZykeBand
Free. Unsubscribe anytime. Closed pre-order in selected EU countries starts in December.5
