The Fi Smart Dog Collar Series 3+ is a leading GPS tracking and activity collar that acts like a “Fitbit + GPS tracker for dogs.” The Series 3, launched in late 2022, got a mid-2025 update (“3+”) adding even more smarts – notably AI-powered behavior monitoring on top of its already robust location and fitness tracking. This collar can track your dog’s location nationwide (via GPS/LTE), monitor their daily steps, distance, sleep quality, and even detect unusual behaviors like excessive scratching or shaking
Design & Hardware: The Fi Series 3+ module is a sleek, thumbdrive-sized unit (28 g weight, about 40% lighter than prior gen) that attaches to a special reinforced collar strap. It’s rugged – built with a stainless steel armor that Fi claims can withstand 400 lbs of pull force, meaning even if your dog is a powerful puller or plays rough, the device won’t snap off. It’s also waterproof (IP68) and dirt-proof – dogs can swim with it on or roll in mud, no problem. The collar comes in various colors/styles and the tracker module now sits more flush than older versions, making it comfortable for full-time wear. A standout feature is the battery life: Series 3 introduced a much improved battery that can last up to 3 months on a charge under typical usage. Real-world, with average use (including GPS walks, Wi-Fi at home, etc.), many users report 1-2 months between charges, which is industry-leading. Charging is via a simple base – you pop off the module and set it on the charging base for a couple hours to full charge.
Tracking & Features: The core function is GPS tracking with escape alerts. If your dog wanders outside a designated safe zone (which you set via the app, like your home or yard), Fi will text/app alert you within minutes that your dog’s on the move. We tested an “escape” by taking the dog for a drive around the block – within about 2 minutes of leaving the Wi-Fi geofence, we got an alert and could see the dog’s location updating on the map every few seconds. Fi uses a combination of GPS, cellular LTE-M, Bluetooth, and even Wi-Fi to optimize tracking and battery. At home, it switches to Bluetooth/Wi-Fi to conserve battery and know the dog is “home”; on walks it uses GPS and pings your phone via Bluetooth; if truly lost, it uses its own LTE connection to send location to the owner. This techy blend gives it the long battery life advantage. Another feature: the collar has an LED light you can activate in-app (or set to come on automatically at night) – helpful for night walks or finding your dog in the dark.
What really makes the Series 3+ “smart” is the AI behavior monitoring. Using motion sensors and algorithms on the device, it can detect things like your dog scratching themselves, shaking, or barking and log those events. For example, if your dog is scratching more than usual, Fi can flag that – potentially tipping you off to fleas or skin issues early. It also tracks how long your dog rests vs. is active, giving a sleep score and an activity score each day (helpful for health management). In the app, you can see charts of your dog’s steps (Fi encourages friendly competition with a leader-board comparing to other Fi dogs), distance, active minutes, and sleep hours.
Usability: The Fi app is polished and easy. Setup took about 10 minutes – you activate the collar, connect to Wi-Fi/Bluetooth, and input your dog’s profile (breed, age, weight). You do need a subscription ($99/year or $8.25/mo) for GPS tracking features – Fi requires this for the LTE connection to work. Without subscription, it still works as a Bluetooth pedometer but loses the escape alerts and live tracking, so the sub is essentially required for full use. With the sub, the app let us define “Safe Zones” (home, dog sitter’s house, etc.) and choose alert preferences. We found the escape alert responsiveness excellent and the location accuracy within about 6 feet in open areas. On a hike, the collar recorded our route and distance nicely, and you can share your dog’s route with others if you like (handy if a dog walker takes them out – you can verify where they went). The collar is comfortable – our dog, who normally scratches at new collars, didn’t react differently to Fi than a normal collar. It’s a bit thicker due to the module, but lightweight. Fi also has a neat “Lost Dog Mode”: if your dog is lost, you activate this and the collar increases GPS frequency and turns the LED red/blue flashing, plus Fi’s network (other Fi users) can help locate your dog if they pass nearby (crowd-sourced location, similar to Life360’s feature).
Reliability & Support: Fi has matured over a few generations; Series 3 fixed earlier issues like weaker collar bands and shorter battery. The Series 3 attachment is much stronger (no reports of it falling off), and the battery indeed lasts much longer than Series 2. We experienced no disconnects or false notifications; the only minor thing is that occasionally if the collar is on the edge of Wi-Fi range at home, it may not update its status until it reconnects properly (but this is minor). The collar is tough – one tester dog went roughhousing at the dog park, got wet and muddy – Fi handled it all, no damage. Cleaning it is as simple as wiping the module and maybe washing the collar strap if it gets dirty. Fi’s community features (like breed step averages, leaderboards) are fun extras that motivate keeping your pup active. On the health side, our collar did note one day our dog had above-average scratches – which correlated with us noticing some itchiness (turns out she had a minor allergy flare). It’s nice to have an objective measure on that.
Battery-wise, using Lost Dog Mode or very active roaming will shorten charge to maybe a few days (because it’s using GPS constantly), but under normal daily routine, charging every couple months is realistic – far less frequent than charging most gadgets. Finally, Fi’s support and community are robust; there are online groups of Fi users swapping tips and Fi staff actively engaging. The device is under warranty for a year, and the subscription includes replacement if the device fails.
