Guide6 min read
How Sleep Trackers Actually Work (And Where the Science Says They Fail)
Sleep trackers use heart rate, motion, and temperature to estimate sleep stages. Here is what published research says about how accurate they really are.
Guides
AI-built from peer-reviewed research, manufacturer specifications, FDA filings, and aggregated user reports. No first-person testing.
Guide6 min read
Sleep Tracker Accuracy: What the Published Research Actually Shows
What does 79% PSG agreement actually mean? A guide to understanding sleep tracker accuracy data, validation studies, and why no consumer device exceeds 80%.
Guide6 min read
Sleep Tracker Subscription Costs: What You Actually Pay Over Two Years
Complete cost breakdown for 6 major sleep trackers. Hardware, subscriptions, free tiers, and 2-year totals from $160 to $480. What each subscription tier includes.
Guide6 min read
Sleep Trackers and Health Screening: What FDA Clearance Actually Means
Which sleep trackers have FDA clearance? What does 510(k) mean? Understanding sleep apnea screening, SpO2 monitoring, and the line between screening and diagnosis.