The three parts working together
A GPS dog collar generally combines three technologies. The GPS chip talks to orbiting satellites to calculate its exact position, the same way your phone's maps app does. A cellular radio inside the collar then sends that position data over the mobile network to a server, which is why most trackers need their own tiny SIM card and a data subscription, separate from your phone plan. Finally, a companion app on your phone pulls that data and shows it on a map, often with a trail of recent movement and an alert system layered on top.
Why there's a delay, and why battery matters
Constantly calculating GPS position and transmitting it over cellular data uses meaningful power, so most trackers don't update in true real-time, they ping their location every few seconds to a few minutes, and some models let you choose a more frequent "live tracking" mode that drains the battery faster in exchange for tighter updates. This is a genuine trade-off: a tracker checked every 30 seconds gives a much better picture of a running dog's path than one checked every five minutes, but it also needs charging far more often, so match the setting to the actual situation, normal daily wear can use a longer interval, and you can switch to live mode the moment your dog actually goes missing.
What breaks the accuracy
GPS accuracy depends on a clear "view" of the sky, so anything that blocks that, dense tree canopy, tall buildings, being indoors, deep valleys, or bad weather, can push the reported location off by tens of metres or cause it to drop out completely. Cellular coverage is the second weak link: even a perfectly clear GPS signal is useless if there's no mobile network to send the data through, which matters a lot in rural or remote areas. Most collars fall back to showing the "last known location" when either signal drops, and some add a short-range Bluetooth beacon as a backup for finding a dog at very close range when cellular fails entirely.
What the numbers on the box actually mean
Manufacturer claims like "accurate to 3 metres" and "battery life up to 7 days" are measured under ideal conditions, open sky, moderate temperatures, and standard (not live) tracking mode. In practice, cold weather drains batteries faster, live tracking can cut battery life by more than half, and accuracy in built-up suburbs or bushland is often noticeably worse than the open-field number on the packaging. It's worth reading independent reviews from owners in terrain similar to yours rather than relying purely on the spec sheet.
Fitting it into daily use
Because of the delay and the coverage limits, a GPS collar works best as a "find my dog if this ever happens" safety net rather than a live leash replacement, it tells you roughly where your dog went after the fact, it doesn't prevent them from getting loose in the first place. Pairing it with a secure collar or harness fit, a properly maintained yard boundary, and a geofence alert set to your property line gets you the fastest possible warning the moment something goes wrong.
