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Connect your WHOOP strap to Sixteen. No WHOOP membership needed.

Sixteen is a health app that connects to a WHOOP strap directly over Bluetooth and to Apple Watch through Apple Health. Heart rate, HRV intervals, sleep, recovery and strain arrive on your phone without touching WHOOP's cloud, so a strap with a lapsed membership keeps working, and you pay for the app once instead of a membership.

Get SixteenWhat comes across
Sixteen setup screen with Apple Watch and WHOOP as connect options and Oura and Garmin marked coming soon

How it connects

The data path, exactly.

The strap broadcasts heart rate and beat to beat intervals over Bluetooth Low Energy. Sixteen pairs with it, keeps the connection alive in the background, and catches up on the night when you wake, oldest data first.

Setup

  1. In Sixteen setup, choose WHOOP and put the strap on.
  2. Sixteen pairs with the strap. Accept the pairing request from iOS.
  3. Wear it as usual. The home screen chip shows battery and sync. Sleep and recovery appear the next morning.

What comes across

  • Heart rate, all day and overnight
  • Beat to beat intervals for HRVSixteen computes rMSSD from adjacent beats
  • Sleep detection and sleep stressFrom overnight heart rate and HRV
  • Day strain from heart rate zones
  • Battery and sync status
  • Respiratory rateNot enough beats arrive over Bluetooth to derive it
  • Blood oxygen and skin temperatureNot exposed over Bluetooth
  • Your WHOOP history and journalStays in WHOOP's cloud

Good to know

  • Works with straps that broadcast heart rate over Bluetooth, including WHOOP 4.0.
  • The WHOOP app can stay installed. Sixteen keeps working if you remove it.
  • Keep Bluetooth on. Sixteen reconnects on its own after the phone restarts.

Questions people ask

Can I use WHOOP without a subscription?
The WHOOP app itself locks when the membership ends. The strap is still a heart rate sensor, and Sixteen reads it directly over Bluetooth, so with Sixteen you keep sleep, HRV, recovery and strain from the strap without a WHOOP membership.
Is Sixteen affiliated with WHOOP?
No. WHOOP is a trademark of its owner. Sixteen is an independent app that reads the strap's standard Bluetooth output.
Will my recovery score match WHOOP's?
It will move the same way on the same nights because it uses the same underlying signals, but it is a different model and we do not claim it is more accurate.
Which WHOOP models are supported?
Straps that broadcast heart rate and intervals over Bluetooth. WHOOP 4.0 is tested. Newer straps that keep the same broadcast will work; check the setup screen for the current list.

Keep reading

WHOOP alternative Sixteen vs WHOOP WHOOP cost calculator HRV
Sixteen app iconSixteen

Pay once. Keep your data. Earn your scroll.

Sixteen is $99 once for lifetime access, or $19.99 a month. Connect the wearable you already own. No hardware to buy, no membership that expires.

Get Sixteen for iPhoneSee pricing

iPhone (iOS 17 or later). Prices in USD.