Fitbit’s Versa 4 smartwatch is a fully-fledged fitness tracker with built-in GPS and all the activity measurements you could desire.
Like all Fitbits, it also is a great sleep tracker and boasts an auto-sleep mode that’ll automatically recognise when you’re asleep – no need to set it to a ‘sleep’ mode like with other trackers.
It measures the duration of sleep, and splits this into three Sleep Stages: Light sleep, Deep sleep, and REM sleep.
Alongside Restoration (which measures your sleeping heart rate vs your daytime resting heart rate), it gives you a nightly Sleep Score out of 100, and detailed data on how to improve the quality of your sleep.
As with the top-end Fitbit Sense, the Versa 4 also measures your SpO2 blood oxygen saturation. Nighttime SpO2 is usually lower than daytime SpO2 because your breathing rate is, on average, slower during sleep.
And, of course, you get all the fitness measurements (heart rate, cardio scores, and exercise modes), and smartwatch features (on-wrist phone calls, message notifications) though with the notable omissions of Google Assistant and music control compared to the Versa 3.