If your dog has ever slipped a lead or cleared a fence, you already know the feeling that sends most people to this page. The good news is that a tracker genuinely solves it. The confusing part is that four quite different products are all sold as "dog trackers," and only two of them will actually find a dog who is properly gone.

This guide explains the differences, what to check before you buy, and where Fi fits — including the cases where something else suits you better.

The four kinds of dog tracker

1. Bluetooth tags (AirTag, Tile and similar)

These are the cheapest option and the most commonly misunderstood. A Bluetooth tag has no GPS and no cellular connection. It reports a location only when it passes within Bluetooth range — roughly 10 to 100 metres — of somebody else's phone that is part of the same finding network.

In a dense city that can work surprisingly well. On a country lane, a beach or a forest trail, there is nobody to relay the signal, and the tag shows you the last place it was seen rather than where your dog is now. There is also no live view: you cannot watch a dog move.

Good for: knowing which room the collar is in, or a cheap backup on a second collar. Not suitable for: a dog who actually runs.

2. GPS trackers with a cellular connection

These use GPS satellites to work out where the dog is, then send that position over a mobile network to your phone. This is the category most people mean by "dog GPS tracker." It gives you live tracking, movement history and escape alerts, and it works at any distance as long as there is mobile coverage.

The trade-off is a subscription, because the device has its own cellular connection to pay for — the same reason a smartwatch with mobile data costs more to run than one without.

Good for: almost everyone. Watch for: coverage in the places you actually walk, and battery life.

3. Radio and handheld systems (Garmin and similar)

Built for hunting and field work. A collar transmits to a dedicated handheld receiver over radio, with no mobile network involved, which means they keep working in genuine wilderness where nothing else does. They are heavier, considerably more expensive, and you have to carry the handheld.

Good for: hunting dogs and remote back-country work. Overkill for: a garden escape artist.

4. Containment collars

These create a virtual boundary and correct the dog — usually with sound, vibration or static — when they approach it. Tracking is often a secondary feature. Whether you want a collar that corrects your dog is a training philosophy question rather than a technical one, and worth deciding separately from the tracking question.

What to check before you buy

Coverage where you actually go

A cellular tracker is only as good as its network. Check the manufacturer's published country list rather than assuming, and check it against the places you take your dog — not just where you live. Coverage that stops at a national border matters if you travel.

Battery life, measured honestly

Battery figures vary enormously across the category — from a few days to a few months — and they depend heavily on how often the device reports its position. A tracker that lasts weeks in normal use may last hours in live-tracking mode. Ask what the number assumes.

Weight, against your dog's size

This is the specification people skip and then regret. A tracker sits on the collar all day. For a small dog, a heavy device is a genuine welfare issue, and it is the main reason trackers end up in a drawer. As a rough guide, look for something under about 25 g for a dog below 10 kg.

Water resistance

Look for an IP rating rather than the word "waterproof," which means nothing on its own. IP68 is the level that covers swimming and sustained submersion. If your dog swims in the sea, salt-water testing is worth asking about, because salt is harder on electronics than fresh water.

Escape alerts, not just tracking

There is a real difference between a device that tells you where your dog is when you ask, and one that tells you the moment they leave the garden. The second is what actually prevents a lost dog. Check whether alerts are instant and whether you can set more than one safe zone.

Do you need a subscription?

For a live GPS tracker, almost always yes — and it is worth understanding why rather than treating it as a trick. The device carries its own SIM and its own data connection. Somebody has to pay the mobile network every month.

Trackers advertised without a subscription are usually Bluetooth tags, which have no cellular connection to fund and, as above, no ability to find a dog who has genuinely run. There is no meaningful free live GPS dog tracker, and any product promising one is worth reading closely.

The sensible way to compare is total first-year cost — hardware plus twelve months of service — rather than the headline hardware price.

Is an AirTag good enough for a dog?

For most dogs, no, and the reason is structural rather than a matter of quality. An AirTag depends on other people's devices being nearby to report a location. That assumption holds in a busy city and collapses in exactly the situations where a dog goes missing — open country, woodland, at night.

It also cannot show you live movement, which is what actually lets you catch up with a dog rather than follow them around after the fact.

Where Fi fits

Fi makes live GPS trackers in the second category. Three models, and they suit different dogs:

Fi Series 3+

The full smart collar. 47 g, up to 3 months of battery, IP68 and IP66K rated and salt-water tested, with a collar band rated to over 500 lbs of pull resistance. It charges on a wireless base that also extends Wi-Fi coverage. Alongside location it tracks activity, sleep, barking, scratching, licking, and eating and drinking.

Fi Mini

A 16 g module that attaches to a collar you already own, so it suits small dogs and cats where a full smart collar is too much hardware. Up to 2 months of battery, IP68, USB-C charging.

Fi Ultra

Built for dogs who go beyond mobile coverage. It adds satellite connectivity through T-Satellite powered by Starlink, plus Fi CallBack™. It is 69 g with up to 5 days of battery — the trade-off for the satellite radio.

The things worth knowing before you choose Fi

We would rather you find these here than after ordering:

  • All three require a membership. Series 3+ is $189 for the first year with the device included. Fi Ultra is $388 — a $199 hardware kit plus the $189 annual membership.
  • Fi Ultra is United States only. Even with satellite connectivity it is not supported internationally, and satellite coverage excludes Alaska.
  • Series 3+ and Fi Mini work across 35 countries and territories in North America and much of Europe — so check the list if you travel with your dog.
  • Fi Ultra is thicker on the collar than most alternatives at 24.5 mm, because of the satellite hardware.
  • Every Fi comes with a 30-day risk-free trial, which is the honest way to find out whether coverage works on your actual walks.

Common questions

What is the best tracker for a dog?

For most dogs, a GPS tracker with a cellular connection, chosen on coverage where you walk, battery life and weight relative to your dog. For hunting and back-country work, a radio handheld system. For a dog who never leaves a city flat, a Bluetooth tag may be enough.

What is the best dog tracker without a subscription?

Any subscription-free option will be a Bluetooth tag rather than a live GPS tracker, because there is no cellular connection to pay for. That is a reasonable choice if you mainly want to find a collar around the house — but it will not find a dog who has run.

Is there a free dog GPS tracker?

No. Live GPS tracking needs a mobile data connection, and that has a running cost. Products marketed this way are generally Bluetooth tags.

Do dog trackers work without phone signal?

Standard cellular trackers need mobile coverage to report a position. Satellite-capable devices such as Fi Ultra, and radio handheld systems, are the two ways around that.

How heavy is too heavy?

As a rough guide, under about 25 g for a dog below 10 kg. Above that, most dogs are comfortable with 40 to 70 g, though a lighter device is always kinder on the neck over a full day.