What's the best fitness tracker for sleep tracking?

WHOOP 5.0 is the most sleep-focused option here — it has no screen, is built to be worn 24/7, and reddit r/whoop users repeatedly call out sleep and stress monitoring as its strongest feature. Fitbit's Inspire 3 also has well-regarded automatic sleep tracking and a Sleep Score, and it's far cheaper since it has no required subscription beyond the included trial.