launching november on 
Add health tracking to the watch you love
Meet HIYD: a 2.7mm sensor that adds advanced fitness and health tracking to your favourite watch, with zero monthly fees.
Join 16100+ in getting a free gift when we launch on Kickstarter!
Sign up and secure our lowest price when we launch
Connecting at the industry's Main stages From San Francisco to Geneva
We regularly attend the world's biggest watch showcases and events. See HIYD in person.
Why compromise your style? HIYD was designed to be hidden
Tired of bulky smartwatches, clunky fitness bands and rings? HIYD is an ultra-slim 2.7mm sensor that hides quietly under your favourite watch. Giving you full fitness tracking without changing your style and with zero monthly fees.
How HIYD works Simple setup. Seamless tracking.
HIYD secures to the back of your watch using a unique microsuction design. No glue. No magnets. No marks. No tools. Swap it easily between your favourite watches in seconds. It's safe to use, and will not fall off.
STICK
Apply HIYD to the back of your favourite watch. It sticks securely and invisibly behind your case-back.
WEAR
Wear and enjoy your watch while HIYD tracks all your health and fitness metrics in the background.
SYNC
Seamlessly connects with both iOS and Android for fast, intuitive syncing right out of the box.
Hardware and software Perfectly aligned.
HIYD pairs precision hardware with beautifully executed software to track your sleep, steps, heart rate, and recovery. We even included a built-in nutrition and calorie tracker that uses your phone camera as a personal nutritionist, effortlessly tracking your calories and macros. It is intuitive, powerful, and compatible with both iOS and Android.
Sleep quality incl. sleep score and stages
Daily health and readiness overview
Activity, steps, and heart rate monitor
Scans calories, macros and daily nutrition
Health tracking with no monthly fee Sign up and secure your spot.
How HIYD compares Beauty meets brains
HIYD delivers a blend of style, comfort, and advanced technology, not to mention zero monthly fees. Tracking never looked (or felt) so good.
| Feature | Hiyd | Screenless Tracker | Smartwatch | Smart Ring |
|---|---|---|---|---|
| Sleep Tracking |  | | | |
| Daily Readiness (RHR/HRV) | | |  | |
| Nutrition Tracking | | | | |
| Gym Friendly | | | | |
| True Style Customisation | | | | |
| Base Price | £149* | £169 | £369 | £399 |
| Monthly fees | £0 | £19+ | £0 | £6 |
*£149 is our early bird launch price, after £80 off.
Try HIYD risk-free Guaranteed fit or your money back.
Worried that HIYD won’t fit your favourite timepiece? We’ve got you covered. If HIYD doesn't securely attach to your watch, return it within 30 days for a full refund. No questions asked. The perfect fit, guaranteed.
Sign up now for exclusive early access VIP Spots are limited!
Join our early community to lock in exclusive pre-launch perks, special backer pricing, and behind-the-scenes updates before we launch.
By watch enthusiasts. For watch enthusiasts.
Don't compromise your favourite timepiece just to track daily steps and calories. HIYD was designed by people who care deeply about horology. Crafting a seamless, ultra-thin sensor that respects the character of your watch while keeping you connected to your health goals. Check out some reactions to HIYD from the community.
Built by the people behind the tech you already love.
Before HIYD, our team built products at places like Apple and Tesla. But we’re watch enthusiasts first. We got tired of strapping bulky plastic trackers next to our vintage pieces, so we engineered a solution ourselves. We're excited to launch HIYD this November exclusively on Kickstarter, and we hope you sign up and join the VIP list.
Secure your VIP spot today. Sign up now and get a free gift!
Get priority access, exclusive updates, and super early-bird pricing when we launch this November on Kickstarter. It's 100% risk-free.
Frequently asked questions
What health data does HIYD track?
HIYD tracks the metrics that matter most for your fitness and health, all in the HIYD app:
- Sleep quality, including sleep score and sleep stages
- Heart rate
- Resting heart rate (RHR) and heart rate variability (HRV)
- Daily readiness and recovery
- Activity and daily steps
- Calories, macros and daily nutrition, scanned with your phone camera
Can HIYD damage my watch?
Absolutely not. We use industrial-grade microsuction instead of messy adhesive glues or harmful magnets. It holds HIYD securely in place during daily wear, yet peels off completely clean, leaving zero residue, marks, or scratches behind, even on delicate polished gold, platinum, and glass casebacks.
What about workouts, sweat and sleep?
Absolutely. Some users prefer to keep HIYD on their watch 24/7 through workouts and sleep, while others prefer to slip the sensor into the soft, comfortable band included with your order. HIYD works seamlessly either way. It’s fully sweat-proof and slip-proof, engineered to stay firmly in place no matter how intense your training gets. Guaranteed, or your money back.
What if I don't want to wear a watch when I work out or sleep?
No problem. Slip the sensor into the HIYD Softband, the soft, comfortable band included with your order, and leave your watch on the nightstand. Your tracking carries on through workouts and sleep, and when you're ready, simply move HIYD back to your watch.
Will HIYD fit my specific watch size or style?
The sensor is engineered with a universal profile that fits 95% of watch casebacks. If you're in doubt send us an email and we'll confirm the fit. If your HIYD doesn't securely attach to your watch, return it within 30 days for a full refund. No questions asked.
How big is HIYD?
HIYD is 2.7mm thick and 25mm in diameter. We are continuously working to make it even thinner.
When will I actually receive my HIYD?
We are in final pre-production right now, and VIP depositors will get priority access to the final launch later this year. The first batch will ship by Q2 2027 at the latest.
We know the hardware space comes with baggage and everyone has heard horror stories about projects ghosting or running years behind. But we aren't learning on your dime. We’ve already successfully launched V1, and this launch is for our 2nd Generation HIYD: thinner, more accurate, and with a significantly better battery. We know how to manufacture, ship, and deliver because we've done it before.
Buy with confidence. We are a US-based company out of California, fully transparent about who we are, with zero dodgy middlemen or anonymous overseas operations.
How do you ensure data privacy and security?
We use enterprise-grade encryption for all sensor data storage and transmission, keeping your information completely secure. More importantly: we NEVER sell or share your personal data. Ever. Your health and movement metrics are yours, and yours alone.
How long does the battery last?
You get a full 4 days of continuous, around-the-clock health tracking on a single charge, through your workouts, your workdays and every night of sleep tracking.
Rather never think about charging at all? Pair HIYD with the Battery Band, which charges your sensor seamlessly overnight while you sleep. You never have to take it off to charge if you don't want to, so it feels like infinite battery life.
How do I charge HIYD?
Two easy ways. The Battery Band has a built-in charger that charges your HIYD sensor while you sleep, so you wake up topped up and ready to go without ever taking it off. Otherwise, you can use the standalone charger.
Does HIYD interfere with automatic watch winding?
Not at all. The sensor is completely non-magnetic and ultra-thin at just 2.7mm, engineered specifically so it will not interfere with the internal mechanics, balance wheel, or the automatic winding rotor of your mechanical timepiece. Your watch keeps ticking and winding exactly the way it was designed to.