Product Review · Pet GPS Trackers · #5 Ranked
Fi Series 3+ GPS Dog Collar
GPS trackers · Reviewed by Katie · amazon.com live, Sept 28 2026
Why it scored a 78
GPS+cellular (AT&T LTE-M); Escape alerts/virtual fence; Health & behavior monitoring. Features is the standout at 88; Warranty trails at 55.
What you're getting
- GPS plus AT&T LTE-M cellular for live location tracking
- Escape alerts with virtual fence (geofence) safe zones
- Health and behavior monitoring plus activity and sleep tracking
- Waterproof collar with built-in LED for night visibility
- Apple Watch compatible alongside the phone app
- Requires an active Fi membership; tracking stops without it
ViperScore breakdown
Should you buy the Fi Series 3+ GPS Dog Collar?
The Fi Series 3+ GPS Dog Collar is built for owners who want a full smart collar, not a tag: live GPS over AT&T LTE-M, escape alerts, and daily activity and sleep tracking rolled into one waterproof collar with an LED for night walks. The $129.00 hardware price hides a required $99 six-month membership, so the real cost is in the plan. It is a reasonable pick for an active dog owner who already tracks their own steps and wants the same for the dog.
Where it earns its score
- Features score 88. Live tracking, geofence safe zones, health and behavior monitoring, activity and sleep, and Apple Watch support in one device.
- Cheap to get started. Hardware is $129.00, so the barrier to trying it is low compared with the $599 Halo Collar 5.
- Collar, not a clip-on. The tracker is integrated into a waterproof collar, which removes the risk of a tag holder snagging or falling off.
- LED for night visibility. A built-in light makes the dog easier to see on evening walks.
What to know first
- Membership is the product. $99 per six months, and tracking stops entirely without it. Value scores 70 for that reason.
- Single carrier. It runs on AT&T LTE-M only, so check coverage where you walk and hike. The Halo Collar 5 uses all three major carriers.
- Dog only. This is a dog collar; cats need the Tractive GPS CAT Mini.
- Warranty is the weakest ViperScore factor. At 55, Fi's coverage is short for a device you are committing to a recurring plan on.
Our verdict
The Fi Series 3+ scores 78, Fair Buy, ranked #5 of 8 pet GPS trackers. Quality and features are strong; the membership model is what holds the score down. Buy it if you want activity data alongside location and are fine with the plan. For pure lost-dog tracking, the Tractive GPS DOG 6 at $55.30 is the simpler buy.
Tractive GPS DOG 6
Questions buyers ask
How much does the Fi Series 3+ cost per month?
Membership is $99 per six months, roughly $16.50 a month, on top of the $129.00 collar. GPS tracking does not work without an active membership.
Does the Fi collar work without a subscription?
No. Location tracking, escape alerts and activity data all stop when the membership lapses.
Is the Fi Series 3+ waterproof?
Yes. The collar is waterproof and suitable for swimming and rain, and it has a built-in LED for night visibility.
Ready to check it out?
Fi Series 3+ GPS Dog Collar · ViperScore 78 · Fair Buy · $129.00
How the other 7 pet gps trackers scored
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