Often run the same route which with my polar flow watch is 5km yet I ran it yesterday using strava on my iPhone and it was 5.25km. To me, that’s quite a big difference in accuracy. Any thoughts as to which is more accurate?
I have a Garmin Fenix 6 Pro, a Polar Grit X and a Suunto Spartan Ultra which all track within 1% or so on distance and, where it’s been an event, matched closely the listed distance. I’m therefore sure they are accurate, at least enough for my needs.
Never tracked with my iPhone so can’t say how that does.
Have you looked at both in Strava to see how close to the route you went the tracking is? That will give you some indication which is likely more accurate.