Geofencing can be very accurate, but it is not perfect. There are a few factors that can affect the accuracy of geofencing, including the location of the user, the size of the geofenced area, and the type of device being used.
User location is the most important factor in determining the accuracy of geofencing. If a user is moving, their location can be more difficult to pinpoint. Geofencing is also more accurate in urban areas, where there are more GPS satellites, than in rural areas.
The size of the geofenced area can also affect accuracy. A smaller area will be easier to track than a larger one. And, finally, the type of device being used can make a difference. Smartphones are generally more accurate than other types of devices, like tablets or laptops.