The Fi Mini is the smallest dedicated GPS pet tracker worth buying in 2026. At 16 grams and 42 x 30 mm, it clips onto any existing collar or harness without replacing your gear. GPS accuracy matches the Fi Series 3, battery runs up to 3 weeks standalone (3 months with the optional base station), and it works for both dogs and cats. The catch: you need a subscription starting at $8.25/month on the annual plan.
Fi launched the Mini in September 2025 as a direct answer to the biggest complaint about GPS pet trackers: they’re too bulky. After testing it on two dogs and one skeptical cat, the results are clear. This is the tracker that finally makes GPS practical for pets under 15 pounds.
- 16 grams and clips to any collar from 3/8-inch to 1-inch width, no collar replacement needed
- GPS + LTE-M + Wi-Fi + Bluetooth tracking covers outdoor, indoor, and close-range scenarios
- 3-week battery standalone, extendable to 3 months with the optional base station
- IP68 waterproof and USB-C charging for durability in rain, mud, and shallow water
- $99 device cost with 6-month membership included, then $8.25/month on the annual plan
Fi Mini Size and Build Quality
The Fi Mini measures 42 x 30 mm and weighs 16 grams. For context, that’s lighter than three quarters stacked together. The Fi Series 3 smart dog collar module weighs 28 grams and requires a proprietary collar band. The Mini clips onto whatever collar your pet already wears.
The clip mechanism locks onto collar bands between 3/8 inch and 1 inch wide. It stayed secure through every test we threw at it.
This size difference matters most for cats and small dogs. A 28-gram module on a 5-pound cat is noticeable and can affect how they move. A 16-gram clip is not. We tested it on a 9-pound tabby who didn’t react to the tracker at all.
One trade-off: the smaller body means a smaller battery. The Series 3 gets up to 3 months of battery life. The Mini tops out at 3 weeks without the base station.
How Does the Fi Mini Track Your Pet?
The Fi Mini uses four tracking technologies layered together:
GPS + LTE-M handles outdoor tracking. The tracker connects to GPS satellites for positioning and sends that data over Verizon’s LTE-M cellular network. LTE-M reaches about 30% farther than standard 4G in rural areas, according to Fi’s official Mini specs. In open outdoor areas, we measured accuracy within 8-12 feet consistently.
Wi-Fi kicks in when your pet is indoors. The tracker detects nearby Wi-Fi networks to estimate location without burning through GPS battery. This is how the base station extends battery to 3 months. When the tracker stays within Wi-Fi range, GPS mostly sleeps.
Bluetooth provides close-range finding when your pet is nearby but hiding. Works within about 30 feet.
In dense urban testing with tall buildings, accuracy dropped to roughly 20-30 feet. Under tree cover on trails, it held within 15 feet. Underground parking garages and basements were dead zones, as expected for any satellite-based tracker. The key takeaway: if there’s cell coverage, the Fi Mini finds your pet.
Battery Life: 3 Weeks or 3 Months
Fi claims up to 3 weeks standalone and up to 3 months with the base station. In our testing across 4 weeks, here’s what we actually measured:
Standalone (no base station): 17 days with a mix of indoor and outdoor time. Our test dog spent roughly 6 hours outdoors daily. The tracker checked in at intervals during quiet periods and ramped up during walks and off-leash time.
With base station: We didn’t hit the 3-month mark in our testing window, but after 4 weeks the battery showed 72% remaining. The math checks out. The base station keeps the tracker on Wi-Fi, which dramatically reduces GPS and cellular usage.
Lost Pet Mode: continuous tracking drains the battery in roughly 48 hours. That’s comparable to the Fi Series 3 in the same mode. Continuous GPS + LTE transmission is power-hungry on any device this size.
Charging uses USB-C and takes about 90 minutes from empty. A welcome upgrade from older Fi products that used proprietary magnetic chargers.
Hot
Fi Mini App and Escape Alerts
The Fi app handles everything: live tracking, geofence setup, activity monitoring, and escape alerts. Setting up geofences (Fi calls them “Safe Zones”) takes about 30 seconds. Draw a circle on the map, name it, done.
Escape alerts are the core feature. When your pet leaves a Safe Zone, the app sends a push notification with the last known location and a live tracking map. In our testing, alerts arrived within 15-30 seconds of the pet crossing the boundary. Fast enough to react before a dog reaches a busy road.
Activity tracking counts steps, monitors sleep patterns, and tracks exercise goals. Fi recently announced AI-powered behavior detection that will flag changes in barking, scratching, and eating habits. These AI features are rolling out gradually through 2026, according to Fi’s September 2025 announcement.
The app supports multiple pets on one account. Each pet gets its own profile, activity goals, and Safe Zones.
One limitation worth flagging: the Fi app is US-only. Zero international coverage. If you travel abroad with your pet, the tracker won’t update until you’re back on US cellular networks. For international trips, you’d need to swap to a Tractive tracker, which covers 175+ countries but uses a different app entirely.
How Much Does the Fi Mini Cost?
The pricing structure bundles the device with a subscription:
| Plan | Device + Membership | Monthly Cost After |
|---|---|---|
| 6-month bundle (Amazon) | $99 | $14.99/month |
| 12-month bundle (Amazon) | $129 | $14.99/month |
| Annual renewal | — | $8.25/month ($99/year) |
The cheapest path: buy the $99 bundle on Amazon, then switch to annual renewal at $99/year. First-year total: $99 + $99 = $198. Each additional year: $99.
For comparison, the Tractive GPS DOG 6 costs $49.99 for the device plus $5/month on the annual plan ($60/year). First-year total: $110. Fi costs more, but you get a smaller tracker with longer battery life.
The no-subscription GPS trackers avoid ongoing costs entirely, but most use Bluetooth networks instead of cellular GPS. Different trade-off.
Fi Mini vs Fi Series 3
| Feature | Fi Mini | Fi Series 3 |
|---|---|---|
| Weight | 16g clip-on | 28g collar module |
| Battery (standalone) | Up to 3 weeks | Up to 3 months |
| Waterproof | IP68 | IP68 + IP66K |
| Works for cats | Yes | No |
| Charging | USB-C | Magnetic base |
| Price | $99 (6-mo bundle) | $149 |
Choose the Mini if: you have a cat, a small dog, or you want to keep your existing collar. The clip-on design is the Mini’s biggest advantage.
Choose the Series 3 if: battery life is your top priority and you have a medium-to-large dog. Three months between charges with no base station is unmatched. The smart dog collar form factor also means one less thing to manage.
Who Should Buy the Fi Mini
The Fi Mini fills a specific gap in the GPS tracker market for small pets. It works best for:
Cat owners. The Fi Mini at 16 grams is one of the only GPS trackers light enough for cats. It clips to breakaway collars safely.
Small dog owners. Dogs under 15 pounds benefit from the lighter weight. Breeds like Yorkies, Chihuahuas, and Miniature Dachshunds can wear it comfortably. We tested on a 7-pound Yorkie mix for two weeks with no collar fatigue or behavioral changes, which is more than we can say for the 28-gram Fi Series 3 module on the same dog.
Multi-pet households. One app, multiple trackers, shared subscription tier. If you have three dogs and a cat, one account covers all four.
Existing collar loyalists. The Mini clips onto tactical collars, designer collars, training collars, harness straps. No replacement needed.
Skip it if you need 3-month battery life without a base station or international coverage.
Apple’s cross-platform tracker detection standard means the Fi Mini can be detected by both iOS and Android devices if someone places one on your belongings without consent. This is the same unwanted tracking protection that covers AirTags and other Find My network accessories.
Bottom Line
The Fi Mini delivers real GPS tracking in a package small enough for cats and toy breeds. At 16 grams with a clip-on design, it solves the two biggest problems with pet GPS: weight and collar compatibility.
Battery life is shorter than the Series 3, but 3 weeks is plenty for most owners who charge devices regularly. The subscription at $8.25/month (annual) adds up to nearly $100/year on top of the device. That’s the real cost to weigh. But if knowing your pet’s exact location matters to you, and Bluetooth-only trackers like AirTags don’t cut it for real-time tracking, the Fi Mini earns its price.
FAQ
Does the Fi Mini work for cats?
Yes. The Fi Mini weighs 16 grams and clips onto any collar between 3/8 inch and 1 inch wide, including breakaway cat collars. Fi explicitly markets the Mini for cats, making it one of the few dedicated GPS cat trackers available in the US. Most cats over 4 pounds can wear it without issues.
Do you need a subscription for the Fi Mini?
Yes, a subscription is required for GPS tracking. The device uses cellular networks to transmit location data, and the subscription covers that connectivity. The most cost-effective option is the annual plan at $8.25/month ($99/year). Without an active subscription, the tracker can't send location updates.
How does the Fi Mini attach to a collar?
The Fi Mini uses a clip mechanism that locks onto collar bands between 3/8 inch and 1 inch wide. You slide the tracker onto the collar band and it clicks into place. No tools needed, and it fits most standard flat collars and harness straps. The clip held securely during all our testing activities including running, digging, and roughhousing.
What is the range of the Fi Mini GPS tracker?
The Fi Mini tracks anywhere with cellular coverage in the United States. It uses GPS satellites for positioning and LTE-M cellular networks to transmit data. There is no fixed "range" like Bluetooth trackers. If your pet is in an area with cell service, the tracker works. Bluetooth proximity finding works within about 30 feet for close-range locating.
Can you track multiple pets with one account?
Yes. The Fi app supports multiple pet profiles under one account. Each pet gets its own tracker, activity goals, and Safe Zones. Adding a second pet requires buying another Fi Mini device and adding it to the same subscription tier.
Does the Fi Mini work internationally?
No. The Fi Mini only works within the United States. It relies on US cellular networks for data transmission. If you travel abroad with your pet, the tracker won't update until you return to US coverage. For international pet tracking, consider the Tractive GPS DOG 6, which operates in over 175 countries.
How does the Fi Mini compare to an AirTag for pets?
The Fi Mini provides real-time GPS tracking with cellular connectivity, while an AirTag relies on the Bluetooth-based Find My network. The Fi Mini shows your pet's live location on a map with updates every few seconds in Lost Pet Mode. An AirTag only updates when it passes near another Apple device. For pets that escape to areas without heavy iPhone traffic, GPS tracking is significantly more reliable.
