Fi Mini review: light enough for a cat, with a few catches

What you get

The Fi Mini is a small clip-on tracker, about 1.7 by 1.2 inches and half an inch thick, weighing 16 grams (0.56 ounces). It comes with a strap and a set of soft silicone cases in five colors; either one attaches it to a collar or harness you already own. Fi designed it with smaller dogs and cats in mind. It runs on Verizon's LTE-M network, where Fi's Series 3+ dog collar uses AT&T's, and it's rated IP68, safe to 1.5 meters for 30 minutes. It doesn't need a Fi Base.

What it does for cats, and what it doesn't

The tracking works the same on a cat as on a dog. You see your cat on the live map, set Safe Zones around home and other places, and get an escape alert when your cat leaves one. Lost Mode then switches on live tracking so you can follow your cat in real time, for about 2 days on a full battery.

Health data is where it falls short. Fi's cat FAQ says the Mini doesn't track steps, activity or behavior on cats, because cat movements are too subtle for its sensors to read reliably. Some reviews describe activity and sleep data for cats, but Fi's current FAQ says otherwise, so don't buy it for that. If you want to follow your cat's activity, sleep or resting heart and breathing rates, Tractive's CAT 6 Mini does all of it.

There's no sound to help you find it, either. Fi's spec pages list neither a speaker nor a light, and Cats.com says the tracker doesn't light up or make noise, so a collar that comes off inside the house can be hard to find.

Putting it on a cat safely

Fi doesn't include a collar or say which kind to use on a cat, so this part is up to you. International Cat Care recommends a collar with a snap-open buckle that releases under pressure, fitted so one or two fingers slide underneath. Choose a breakaway collar first, then attach the Mini:

• The strap fits collars and harnesses from 3/8 to 1¼ inches wide.
• The soft case needs a collar at least 1/2 inch wide.

So if your cat's collar is narrower than half an inch, use the strap. As with any breakaway collar, the tracker goes with the collar when it releases. The map then shows where it came off, which is a good place to start looking.

Battery

Fi says the Mini should last up to 2 months, and longer the more time it spends connected to your Wi-Fi or your phone over Bluetooth. That's more generous than Fi's own launch announcement in 2025, which said 3 weeks. Independent reviewers land closer to the launch number: Trail & Kale saw 3 to 4 weeks between charges, and Cats.com lists it at up to 3 weeks. A cat that spends long days away from home will use more.

Lost Mode runs about 2 days on a full charge. To charge, you take the tracker off the collar and plug in the USB-C cable; if it's been wet, let it dry completely first. Put it straight back on afterward. A tracker on the counter can't help.

What it costs

The Fi Mini is $99, and you need a membership to use it. The prices are the same as for every Fi tracker:

You pay for the tracker at checkout, and the membership is charged when you activate it. Fi puts you on the one-year plan by default and gives you 7 days to switch. Every plan has a 6-month minimum, and there's no monthly option. Year one comes to $288, and two years to $438 on the two-year plan. Fi ships free from $100, so a Mini on its own adds $9 shipping. Fi's price list notes that promotions can lower these prices, so check for a current offer.

You can return it within 30 days of purchase; you pay the return shipping, and the membership is canceled when the return arrives. The 1-year warranty requires an active membership.

Coverage

The Mini reports over Verizon's LTE-M network, a low-power network built for devices. Like every cellular tracker, it needs a signal to send your cat's location, so check coverage where your cat actually roams, not just at the house. Fi's help center links the carrier coverage maps. More in do trackers work without cell service?

Where it falls short

• No activity or health data for cats. Fi says cat movements are too subtle for its sensors.
• No sound to find it. A dropped collar indoors can take some searching.
• Bring your own breakaway collar. Fi doesn't include one or recommend one.
• Higher running cost. $189 a year, against $72–$144 for Tractive.
• Off the collar to charge. Easy to forget to put back.
• Fi's support reputation. Fi held 3.3 out of 5 on Trustpilot in October 2026. Common complaints are billing, cancellations and slow support.

Fi Mini vs Tractive CAT 6 Mini

For most cats, we'd pick the Tractive CAT 6 Mini. It's built into a breakaway collar, adds Territory maps and health tracking, has a light and a sound, and costs less to run ($223 in year one). The Fi Mini wins on weight and battery: its tracker is 16 grams to the Tractive's 25, and it goes weeks between charges instead of days. See them side by side.

Questions people ask