Privacy-First
The Most Private Sleep Tracker for iPhone
Snollo is a private sleep tracker for iPhone and Apple Watch that classifies all audio on your iPhone. The saved clips go to your own iCloud, under your Apple ID — on the Apple devices you sign into.
Unlike SnoreLab, Sleep Cycle, and most other sleep apps, Snollo doesn't route your bedroom audio through a Snollo server. Free to download. Uses the Apple ID you already have — no separate Snollo account.
Download Free — Uses Your Apple IDiPhone · iOS 17+ · Apple Watch optional
Why Sleep App Privacy Matters More Than You Think
A sleep tracker that uses your microphone records 6–8 hours of audio from inside your bedroom every single night. That is among the most intimate audio any app could collect — containing your voice, your partner's voice, conversations, and sounds you are entirely unaware of.
Most popular sleep apps send this audio to their own servers for processing. The app receives raw audio from your bedroom, runs it through cloud-based models, and stores the results on infrastructure they control. What happens to that audio after classification varies by company — and is rarely disclosed clearly.
Sleep Cycle's App Store privacy label confirms the app "may track you across apps and websites owned by other companies." SnoreLab has been flagged by Common Sense Privacy for unclear data-sharing policies. Both apps require bedroom audio to leave your device as a core part of how they work.
Snollo's setup removes this risk. Audio is classified on your iPhone, then discarded. Only the event metadata — timestamps, sound categories — and any clips you save get written to your own iCloud, under your Apple ID. The storage is yours, on Apple's infrastructure, under your control.
How On-Device Processing Works
"On-device" is a meaningful technical distinction, not a marketing phrase. Here is exactly what happens to your audio when Snollo is running.
- 1
iPhone microphone captures audio
Your iPhone's microphone records ambient sound. This audio exists only in the device's working memory — it is never written to the file system or transmitted.
- 2
An on-device model classifies the audio
Snollo's sound classifier runs on your iPhone, on Apple's machine-learning hardware. The model outputs a label (snoring, breathing, coughing, sleep talking, silence) and a confidence score in real time.
- 3
Audio is discarded; only metadata is saved
The raw audio is immediately discarded from memory. Snollo saves only the classification result: a timestamp, a category label, and an intensity score. This metadata — and the short clips you choose to keep — go to your own iCloud, under your Apple ID.
- 4
iCloud syncs your sleep history privately
Your sleep metadata lives in your own iCloud, under your Apple ID. It syncs across the Apple devices you sign into, on Apple's infrastructure — under your control.
Private Sleep Tracker Comparison
How Snollo compares to other iOS sleep apps on the data practices that matter most.
| App | Audio processing | Data storage | Account needed | Data sharing |
|---|---|---|---|---|
| Snollo ★ | On-device classification | Your own iCloud | Uses Apple ID | Nothing routed through a Snollo server |
| SnoreLab | Server-side | Cloud | Optional | Unclear (flagged) |
| Sleep Cycle | Server-side | Cloud | Required | May track across apps |
| Pillow | On-device | On-device / iCloud | Required (Premium) | Not stated explicitly |
| AutoSleep | No audio | iCloud | Not required | N/A |
Based on publicly available App Store privacy labels and published privacy policies as of April 2026.
Who Snollo is for
- ✓ You want snore detection where the audio is classified on your iPhone, not uploaded somewhere else
- ✓ You wear an Apple Watch and want REM, Deep, and Light sleep stages alongside snore context
- ✓ Anyone in a shared bedroom concerned about other people's voices being recorded
- ✓ Users who have tried SnoreLab or Sleep Cycle and want an alternative without cloud audio upload
- ✓ People who want meaningful sleep data at no cost, without a recurring subscription
Who Snollo is NOT for
- ✕ You primarily want a phase-aware wake-up alarm — Sleep Cycle has the most refined implementation
- ✕ You want population-level snore score benchmarks — SnoreLab has 170M+ nights of comparison data
- ✕ You need a native watchOS app to start sessions from your wrist — Pillow has a stronger watchOS UI
- ✕ You're on Android — Snollo is iOS-only
- ✕ You need a clinical sleep apnea diagnosis — a sleep study is required for that
From the Snollo blog
Guide
Snollo vs Sleep Cycle: Which Sleep App Should You Use in 2026?
Snollo vs Sleep Cycle on privacy, features, pricing, and Apple Watch support. Sleep Cycle is the most downloaded. Snollo is the most private.
Guide
Snollo vs Pillow: Which Sleep Tracker Is Right for iPhone and Apple Watch?
Snollo vs Pillow on privacy, Apple Watch integration, snore detection, and pricing. Both work with Apple Watch — here's how they actually differ.
Guide
How to Record Snoring on iPhone (4 Steps, Private & Free)
Record snoring on iPhone with an app that processes audio on-device. Four steps — including what to check to protect your bedroom privacy.
Private Sleep Tracking — Frequently Asked Questions
What is the most private sleep tracker app for iPhone?
Do sleep tracker apps sell your data?
What does 'on-device sleep tracking' mean?
Is there a sleep tracker that doesn't require an account?
How does Snollo store sleep data privately?
Try the most private sleep tracker tonight
Free download. Uses your Apple ID. Audio is classified on your iPhone; saved clips go to your own iCloud.
Download Snollo FreeSnollo (formerly Sleep Slip) · iPhone iOS 17+ · Apple Watch optional