(checked 2026-10-10)Small sample (about 170 ratings); the listing includes a 1-month membership.
PCMag's best overall pet tracker and Wirecutter's runner-up: the smallest, lightest tracker either tested, and it clips onto most collars. But about a third of its small number of Amazon ratings are 1 star, with owners saying it falls off the collar or its GPS often doesn't work.
Subscription: Required and bundled with the hardware: $99 with 6 months of service, $189 with 12 months (about $15.75/mo) or $339 for two years (PCMag)
Top complaints
- Falls off or loses GPS for some owners
Amazon's review summary says the device won't stay on the collar for some owners and that GPS often doesn't work for others; reliability and value are mixed. About 37% of ratings are 1 or 2 stars.
- Inconsistent alerts and occasional dropouts
PCMag's escape alerts arrived anywhere from one to nine minutes after the dog left the safe zone, and small safe zones are hard to set. Wirecutter saw it go offline a few times and hiccup when starting live tracking.
- Battery depends on setup; no light
Amazon owners report battery life from fantastic to a couple of days. Wirecutter says it likely runs low much faster without a Fi base and has no light. It's plastic, so it may be less durable than the Series 3+.
What owners love
- Tiny and fits most collars
At 0.56 ounce, it's the smallest and lightest tracker Wirecutter tested. It attaches to most collars or harnesses with silicone straps or cases, and Wirecutter's never budged over several months.
- Long battery for its size
It lasted more than four weeks per charge in PCMag's testing (full to 75% in 10 days). Wirecutter measured 68% after 18 walks versus 71% for the Series 3+.
- Responsive Lost Mode and a polished app
PCMag found Lost Mode location updates speedy and reliable, liked the heat map and walk replays, and found activity and sleep stats accurate. Amazon owners praise its accurate real-time tracking.
- You have a rough, chewing or very active dog
- You want a built-in light
- You need instant escape alerts
- Small and medium dogs
- Keeping your dog's existing collar or harness
- Long battery between charges
Scores (tap for why)
What experts say
- PCMag: Best Overall GPS Pet Tracker and Editors' Choice (4.0, guide updated 2026-09-22): long battery, compact and reliable, though its eating and drinking data was inaccurate.
- Wirecutter (NYT): Runner-up for dogs: nearly as fast and accurate as the Series 3+ and fits most collars, but its battery doesn't last as long. The Fi Mini For Cats went offline several times in its cat test.