AutoSleep vs Calm

AutoSleep is a sleep-tracking app for Apple Watch and iPhone that records sleep automatically in the background, without requiring the user to start or stop a session. It uses heart rate, motion, and (where available) blood oxygen and wrist temperature data to estimate sleep stages, sleep quality, and a running sleep debt total called the sleep bank. The app integrates with Apple Health and HomeKit, offers a smart alarm that wakes users during a lighter sleep phase, and includes an add-on companion app, AutoSnore, for snore detection. It is sold as a single one-time purchase on the App Store rather than a subscription, and processes data on-device rather than through a cloud account.

Calm is a mindfulness platform that offers guided meditations, sleep stories, breathing exercises, and calming music to help users manage stress and improve mental wellbeing. The app combines expert‑led sessions with a soothing UI, making it easy to build a daily relaxation habit. Available on mobile and web, Calm syncs progress across devices and integrates with health apps to track sleep and mindfulness minutes. It serves both beginners and experienced meditators looking for structured, science‑backed content.

• One-time purchase price with no ongoing subscription fees
• Fully automatic tracking that does not require remembering to start or stop a sleep session
• Detailed metrics including sleep stages, SpO2, respiration rate, and wrist temperature on supported hardware
• On-device processing with no account or login required for basic use

• Large, diverse content library
• High production quality with professional narrators
• Cross‑device syncing and offline mode
• Science‑backed programs for specific goals

• Requires an Apple Watch for automatic tracking; iPhone-only use is far more limited
• Advanced metrics like SpO2 and respiration depend on specific newer Apple Watch models
• Interface and terminology (sleep bank, sleep debt) have a learning curve for new users

• Premium subscription required for most content
• Limited customization of session length
• No API for third‑party integration