Sleep Tracking Apps and Devices Compared

If you have ever woken up exhausted and wondered what actually happened while you were asleep, a sleep tracker promises to tell you, and the options range from a free phone app to a full smart ring or mattress sensor. The honest comparison is about accuracy and comfort, because the best tracker is the one you will actually wear all night.Phone apps that track sleep by sound and movement are the cheapest option, but they are also the least accurate, because they can only infer what is happening from a microphone and your phone lying on the bed. Wearables, the watches and rings, are a big step up, tracking heart rate and movement through the night to estimate your sleep stages, and they are accurate enough to give