Activity monitors

Fi Series 3 Smart Collar review

Published 20 June 2026

8.3 / 10 Our score

A smart collar that pairs strong activity and rest tracking with sleep-pattern alerts and breed comparisons, in a rugged collar with excellent battery life. Health insights need a subscription, but the hardware and data are among the best.

Best for: Owners wanting a rugged smart collar with deep stats

From £99.00 checked 20 Jun 2026

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What works

  • Strong activity and sleep tracking
  • Excellent battery
  • Rugged collar
  • Breed comparisons
  • Sleep-shift alerts

What falls short

  • Subscription for full features
  • Heavier collar form
  • Premium price

How it scores

We rate every product in this category on the same criteria, weighted by how much they matter in daily use. Each score is out of 10.

Weighted score breakdown for the Fi Series 3 Smart Collar
Criterion Weight Score Why
Tracking accuracy 25% 8.5 Tracks steps, calories and rest accurately, with sleep-pattern monitoring
Health insights and alerts 20% 8.5 Notifies on shifts in sleep and activity habits; breed and local comparisons
Battery life 15% 9.0 Excellent battery life for a smart collar, weeks between charges
App experience 10% 8.5 Well-regarded app with goals and comparisons
Size, comfort and fit 10% 7.5 Collar-integrated, sturdy but heavier than clip monitors
Subscription value and transparency 10% 7.0 Subscription needed for full features; ongoing cost to weigh Confirm on your exact model before relying on it.
Durability and water resistance 5% 9.0 Very rugged, water resistant, escape-resistant collar
Value 5% 7.5 Premium price plus subscription, justified by build and data
Weighted total 8.3

How we score: each rating combines the manufacturer specification with the weight of feedback from owners and independent reviewers. We do not copy other reviews. The score is our own synthesis, and we show the reasoning so you can judge it yourself.

Key specifications

Form Smart collar
Tracks Steps, calories, rest, sleep patterns
Battery Weeks
Extras Breed and local comparisons
Subscription Required for full features
Build Rugged, escape-resistant

Common questions

Does the Fi collar track sleep?

Yes, beyond steps and calories it monitors rest and sleep patterns and notifies you of shifts in sleeping and activity habits, which can be useful early health signals.

Is there a subscription?

Yes, full features need a subscription, the main ongoing cost to weigh against subscription-free monitors like PitPat or FitBark, though the build and data are excellent.

How is the battery life?

Excellent for a smart collar, lasting weeks rather than days, helped by efficient power management.

Looking at something else? See our gps trackers