Fi has been refining its GPS tracking collars for years, and the Series 3+ represents a meaningful step forward. The headline improvement is 2x better GPS performance over previous models, which translates to more reliable location updates and quicker fixes when you open the app. This matters most when your dog is moving through dense urban areas or near heavy tree cover—situations where older trackers sometimes lag.

The real-world benefit is straightforward: you get a clear, live dot on a map showing exactly where your dog is, anywhere in the country, with no range limits. The escape alerts work through custom virtual fences you set in the app, and they trigger fast when your dog crosses a boundary. Notifications arrive within seconds, giving you time to act before your dog wanders too far. The collar itself is rugged and water-resistant, designed for daily wear through rain, mud, and rough play.

Battery life is the main tradeoff. It uses a nonstandard rechargeable battery that needs charging every few days depending on usage frequency. If you forget to charge it, the tracking stops working entirely. The collar fits dogs from 20 to 120 pounds, but the hardware is bulky enough that small breeds might find it noticeable. For owners who prioritize accurate location tracking over sleek design or marathon battery life, the Series 3+ delivers where it counts.