Symptoms
- Route on the map looks jagged or zig-zagged
- Distance or pace is clearly wrong compared to a known route
- GPS takes a long time to lock at the start of a workout
- Location jumps suddenly mid-activity
Likely causes
- CommonWeak satellite signal from buildings, trees, or cloudsGPS needs a relatively clear view of the sky to get an accurate fix.
- CommonStarted the activity before GPS locked onBeginning a run immediately after starting GPS search causes early inaccuracy.
- PossibleWatch relying on phone's GPS instead of its ownSome watches without built-in GPS use the paired phone's location, which needs the phone nearby.
- PossibleOutdated GPS almanac dataWatches occasionally need a data refresh via Wi-Fi or the companion app for best accuracy.
- Less commonSoftware bug in the mapping algorithmRare firmware issues can smooth or misplace tracked routes.
What to do
- Wait for the GPS icon to show a solid lock before starting your activity, usually 30–60 seconds outdoors.
- Start activities in open areas away from tall buildings or dense tree cover when possible.
- If the watch relies on connected GPS, keep your phone with you during the activity.
- Connect the watch to Wi-Fi or sync with the companion app regularly to refresh GPS assistance data.
- Update the watch's firmware if a GPS-related fix has been released.
- Compare a couple of workouts to see if inaccuracy is consistent or only happens in specific locations.
When to call a pro
If GPS stays consistently inaccurate in open areas after updates and a fresh sync, contact the manufacturer's support, since it could be a sensor defect.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.