On‑device · Private · Free

Your body's data.
Finally yours.

A beautiful companion for your WHOOP and Oura that runs entirely on your own device. No account. No cloud. No subscription. Just your signals, read straight off the band.

Download free See the science

100% on‑device No account WHOOP 4 · 5 · MG Oura Free forever

The NOOP Today screen showing recovery, effort and rest rings over a dusk sky, with stress, fitness age, vitality, HRV and resting heart rate cards.

Your data never leaves your device.

NOOP reads your strap over Bluetooth and does all the maths on your device. No account. No cloud. No server, so there is nothing to breach. No tracking, no analytics, no ads. Your heart, your sleep, your most personal data, never uploaded, never sold, never held to ransom behind a subscription. You own it and you can export it.

0accounts to create

0cloud servers

100%on your device

£0forever

How it works

Two ways to read a strap.
Only one keeps your data.

NOOP The on‑device way

⏱ Your strap captures heart rate, HRV and more

↓

📲 Bluetooth straight to your phone

↓

🧮 On‑device engines score it locally

↓

✓ Your recovery, strain and sleep. Yours alone.

Subscription apps The cloud way

⏱ Your strap captures the same signals

↓

☁ Uploaded to the company's cloud

↓

💳 Scored behind a monthly subscription

↓

🔒 Your data, on their servers, on their terms

The tech

We reverse‑engineered the strap's Bluetooth protocol,
so your data never needs a server.

Your strap already records your heart, HRV and sleep. NOOP reads it directly over Bluetooth, locally, and decodes it on your device. The strap's private protocol was understood through open community reverse‑engineering and re‑verified on real hardware. Interoperability, not impersonation.

⏱

Your strapHeart rate, HRV, motion and more, captured on a band you own. About 14 days held on‑device.

📲

BluetoothRead locally over the strap's private BLE GATT service. No WHOOP or Oura account, no login.

🔑

Decode + checksumThe 0xAA frame envelope is reassembled and CRC‑verified, then decoded. WHOOP 4 uses CRC8/CRC32; WHOOP 5 a CRC16‑Modbus header.

💾

On‑device SQLiteDecoded rows land in a local database (GRDB on Mac and iPhone, Room on Android). On your machine, nowhere else.

🧮

Local analyticsRecovery, strain, sleep and HRV are computed by pure functions, on your device, with no network in the path.

✓

Your screenYour signals, presented beautifully and explained honestly. Yours alone.

The pipeline is strictly one‑directional and on‑device. Nothing is ever sent off‑device. The strap holds about 14 days of history, which NOOP re‑offloads locally over Bluetooth.

⏱

Your strapThe same signals, captured on the band you own.

☁

Their way: uploaded to a company cloudSent to a server, scored behind a subscription, on their terms. NOOP never does this.

Interoperability, not impersonation. NOOP reads a strap you already own over Bluetooth. It never touches WHOOP's or Oura's servers, never impersonates them, and copies none of their software. It is an independent project, not affiliated with WHOOP or Oura, and is not a medical device. Values are approximate, locally‑computed estimates for personal, informational use.

The app

Everything your strap can tell you.
On a screen you own.

Recovery, strain, sleep, HRV, resting heart rate, stress, fitness age and more. Calculated on your device, presented beautifully, explained honestly.

A calmer Today

Your day at a glance, under a sky that follows the time of day.

A deep app, not a dashboard

Coach, workouts, stress, breathing, lab book and more, a tap away.

NOOP More screen listing Coach, Workouts, Health, Lab Book, Stress, Breathe and Intervals.

Every score, explained

Tap any number to see exactly what went into it. No black boxes.

88CHARGE

Know what your body is ready for.

Charge, Effort and Rest, read from your own heart rate and HRV and computed on your device. The same questions the best obsess over, answered without a subscription.

Start free

Supported devices

Bring your own band.

NOOP speaks to the hardware you already own, locally over Bluetooth. No bridge, no account, no cloud login.

⏱

WHOOP 4.0

Fully supported, end to end. The tested path.

Recommended

🔥

WHOOP 5.0 & MG

Live heart rate today, deeper metrics building.

In progress

💍

Oura Ring 3 · 4 · 5

Read locally over Bluetooth, no Oura app.

Beta

A person stretching in soft natural light.

The science

Built on open, published science.

No black box. Every NOOP score traces to peer-reviewed methods you can read and check, computed transparently on your device. We show our working, cite our sources, and say plainly where a number is an approximation.

5+cited methods

0fabricated numbers

100%on your device

Read the science

The greener wearable

The most sustainable wearable
is the one you already own.

Wearables are typically obsolete in two to three years. They are glued shut, hard to repair, and replacement is driven by subscriptions and planned obsolescence rather than failure. Cancel a subscription and a working band can become e‑waste. NOOP keeps the strap you already bought useful for years.

62 Mtof e‑waste generated in 2022, up 82% since 2010 (about 7.8 kg per person)

82 Mtthe level we are on track to reach by 2030 on current trends

22.3%formally collected and recycled, leaving about US$62bn of recoverable materials lost

~30%of fitness trackers and smartwatches are abandoned by their owners

NOOP keeps your strap alive for years: no forced upgrade, no account, and no subscription that can brick it. On‑device means no data‑centre energy burned per reading. Open and local means it can outlive any one company. The greenest thing you can do with a wearable is keep using the one on your wrist.

Sources: UN / ITU / UNITAR Global E‑waste Monitor 2024 (ewastemonitor.info); tracker abandonment from Gartner. NOOP is not affiliated with WHOOP or Oura.

An honest comparison

Same signals. Very different deal.

	NOOP	WHOOP app	Oura app
Price	Free, forever	Subscription	Subscription
Account required	No	Yes	Yes
Sends data to a cloud	Never	Yes	Yes
Works fully offline	Yes	No	No
You own and export your data	Yes	Limited	Limited
One app, multiple bands	WHOOP + Oura	WHOOP only	Oura only

We compare on price, privacy and ownership, where the difference is plain and provable. NOOP is an independent project and is not affiliated with WHOOP or Oura.

Built in the open