Sleep score · Tue Jul 7 → Wed Jul 8
- Total sleep7h 18m
- Efficiency93%
- Deep sleep1h 40m · 23%
- REM sleep1h 54m · 26%
- Latency12m
- TimingAligned
Sleep-science wearable · titanium
Wake with the light you were promised.
Halcyon reads your night the way a sleep lab would — stages, heart-rate variability, skin temperature — then coaches you toward better sleep in a voice that never shouts. Breathe with the ring for a moment. You’re already winding down.
The Halcyon ring doubles as a breath guide: it expands while you inhale for four seconds, holds for seven, and eases back while you exhale for eight.
[ Last night ]
One number, honestly earned.
Every morning Halcyon folds the night into a single score — and then shows its work. Stages, efficiency, timing: nothing asserted, everything measured.
Sleep stages · 10:54 pm — 6:47 am
- Awake 0h 35m
- REM 1h 54m · 26%
- Light 3h 44m · 51%
- Deep 1h 40m · 23%
Coach · tonight
Lights low by 10:40.
Your deep sleep arrives almost entirely in the first third of the night — give it an earlier door. Dim the room at ten, breathe with the ring for two minutes, and let the morning take care of itself.
[ The ring ]
Instruments, worn lightly.
Everything a sleep lab would wire to you, folded into four grams of titanium. No screen, no buzzing, nothing glowing at 3 a.m. It measures; you sleep.
Grade-5 titanium
Lighter than a wedding band, sealed to 10 ATM. Brushed dusk finish, hypoallergenic inner shell. You’ll check twice that it’s still on.
Lab-grade sensing
Infrared and red PPG for pulse and HRV, a research-grade thermistor reading skin temperature to ±0.01 °C, and a 3-axis accelerometer for movement.
A week per charge
Refilled in 40 minutes on its stone cradle. Charge it while you shower on Sunday, then forget it exists until the next one.
On-device first
Sleep staging runs on the ring itself. Nights sync end-to-end encrypted — or stay on your phone entirely. Your sleep is not a product.
[ The science ]
Measured against the gold standard.
Through a two-year beta, Halcyon’s staging was scored night-for-night against polysomnography — the wired-up laboratory standard — and refined until the difference stopped mattering.
1.4Mnights recorded in beta
94.2%agreement with PSG staging
4gof grade-5 titanium
7daysof battery per charge
“We built Halcyon to be forgotten by ten p.m. The best instrument in a sleep lab is the one the sleeper never notices.”
— Dr. Mara Ellison, Chief Sleep Scientist
The night is half your life.
Spend it well.