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Devices differ, sometimes in ways that look like faults. This page puts them next to each other so you know what is normal for yours.

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Sleep

Two permanent gaps worth remembering:
  • Apple Watch cannot tell you how long you took to fall asleep. Apple does not expose it to any app. It will always show a dash.
  • Polar does not report naps at all. Their service has room for one sleep per night, with nowhere to put a second.

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Daily measurements

* Newer models only.

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Activity and training

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Quirks, per device

  • Time to sleep is permanently unavailable
  • Our sleep figures use the Watch alone, so they will differ from Apple’s Health app, which blends every source
  • Charging overnight means no sleep data, which is correct rather than broken
  • The most complete sleep data available here, and our reference
  • The only source providing overnight movement
  • Temperature is a deviation from your own baseline, not an absolute reading — needs several nights to establish
  • Naps are recorded and drawn, but never scored
  • Nightly Recharge works from the very first night, unusually
  • No naps, ever — a vendor limitation
  • Effort ratings entered in the Polar app do not reach us; enter them here instead
  • The sleep score shown is Polar’s own, deliberately not recalculated
  • On iPhone it arrives via Google Health, which drops restless time — your nights will read slightly better here than in the Fitbit app
  • The Google connection needs renewing about weekly during testing
  • Body-composition scales only in this round
  • BIA readings move with hydration; read the trend

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If your device is not listed

Samsung Health is work in progress and Android-only. Anything else will not connect in this round — but you can still log by hand, and a tester whose hardware we cannot read is genuinely useful to know about.