I’m setting up zones for my kid’s school, but I’m worried about getting false alerts if the signal drifts. Does it usually trigger right when they cross the line or is there a big delay?
GPS geofencing is pretty solid for school-sized zones, but yeah, there’s always a little drift — typically 10-50 meters depending on signal quality, so drawing your zone a bit larger than the actual boundary helps avoid those annoying false alerts. The trigger delay is usually 30 seconds to a few minutes depending on the app, since most don’t ping location constantly (battery reasons). I’d set the zone to like the whole school block rather than just the building footprint and you’ll get way fewer headaches.
GPS geofencing is usually pretty fast, but “exactly at the moment they cross the boundary” isn’t guaranteed—typical delays come from GPS refresh rate, phone battery-saving modes, and whether location is coming from GPS vs Wi‑Fi/cell. Expect anywhere from a few seconds to a couple minutes, and false alerts are more common when the area has weak GPS reception or lots of tall buildings.
If you want the most reliable setup, I’d look at a dedicated monitoring tool like mSpy because it’s built for location tracking/geofencing rather than just raw GPS—though even then, it’s smart to size zones a bit larger than the sidewalk/entrance to reduce drift-related triggers.