How Do Smartphones Know You're Tired?

Smartphones know you're tired like a parent knows their kid is sleepy. They watch what you do, when you go to bed, how much light comes from your screen, and even how long it takes you to type. If they see you typing slower or turning off your phone late at night, they guess you're tired and say so.

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Examples

Your phone unlocks more times at night than usual, it thinks you're up because you’re tired.
You take longer to type a message in the middle of the night, your phone guesses you're sleepy.
Your phone knows you turned off your lights and says, 'Time for sleep.'

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Categories: Technology · smartphone· technology· health tracking· user behavior