Last Updated on June 5, 2026 by Kieran Beckles
I’ve used Fi collars on my Alaskan Klee Kai dogs for over three years, including both the original Series 3 and the newer Series 3+. In this review, I’ll cover the features, pricing, pros and cons, and whether I think the Fi Series 3+ is worth buying today.
Fi Series 3+ Smart Collar Quick Verdict |
 We think the Fi Series 3+ is the best overall smart GPS dog collar thanks to its sleek all-in-one design, reliable real-time tracking, safe zones, activity monitoring, and impressive battery life. It’s not the cheapest option, but for dependable tracking in a comfortable, everyday collar, it’s our top pick. |
I started researching the best smart dog collar in the summer of 2023 after a frightening experience with Copper.
Do you want to read our guide to the best smart dog collars?
We ranked the top seven options in our ultimate guide.
During a morning walk, Copper managed to slip his dog collar and chase a coyote up a hill. For five minutes, I had no idea where Copper had gone.
Fortunately, he came back unharmed. But the experience convinced me I needed a reliable GPS dog collar to help me locate my dogs if something similar ever happened again.
After researching the top smart dog collar options, I opted to invest in the latest Fi dog collar to keep Copper and Skye safe.
Note: Fi has since updated the original Series 3 to the newer Series 3+, which is the version currently sold today. Much of my long-term experience applies to both collars.
2026 Update: My dogs have now worn both Fi and Tractive collars for multiple years. This review has been updated to reflect my long-term experience with battery life, tracking reliability, and subscription costs. As always, this article follows our smart collar testing process to ensure accurate, honest, and experience-based recommendations.
Fi Series 3+ Overview
| Category | Rating |
|---|---|
| Comfort | 8/10 |
| Value For Money | 9/10 |
| App Features | 8/10 |
| Battery life | 9/10 |
| Ease of setup | 9/10 |
| Overall rating | 9/10 |
| Price | 7/10 |
| Durability | 9/10 |
| GPS tracking | 10/10 |
My Honest Fi Series 3+ Collar Review
I wanted to start by sharing my experience using the Fi collar over the past three years, including the updated Fi Series 3+ which I upgraded to in early 2026.
We used a Tractive tracker in the UK, but we stopped using it in early 2023 before we moved back to California.
Fi Series 3+ or Tractive?
You can find out which to buy here.
Recklessly, I didn’t consider investing in new dog trackers for Skye and Copper, despite living on my family’s property, which has a half-acre in an area with a lot of wildlife.
Following Copper’s coyote encounter, I decided it was time to invest in a reliable GPS dog collar.
The Fi smart collar was my top choice because I really liked how the Fi collar series offers an integrated design that was easy to use, hassle-free, simple to charge and has a streamline appearance.
I’ve only charged Skye’s Fi GPS dog collar three times in the past six months. That’s the longest battery life of any GPS dog tracker that I’ve tried and tested.
It’s simple to charge – just attach the Fi Series 3+ to the Fi base. I love having the Fi base rather than fussing with cables. It’s a small thing, but the Fi base is convenient.
Copper and Skye appear to enjoy wearing the Fi collar much more than other trackers we’ve used. It’s relatively lightweight and barely noticeable on their neck.
Although we live in an area with a patchy T-Mobile cellular network, I’ve used the Fi app to find my dog’s location during practice runs in the event Copper or Skye left a safe zone.
In my experience, the Fi collar offers accurate and reliable tracking, so I feel good knowing that it’ll find either of my pups’ location. The Fi Series 3+ uses AT&T, which works fine near me.
While I invested a lot of money in the Fi Series 3+ dog collar, I believe it’s worth the price considering the peace of mind their service provides – which I can’t put a price on!
What I Like vs What I Don’t Like
| What I like about Fi Series 3+ | What I don't like about Fi Series 3+ |
|---|---|
| Escape alerts | Mini does the same thing but smaler |
| Excellent battery life | Subscription required |
| Lost dog mode | Cellular coverage matters |
| Durable constuction | Bulky |
| Reliable GPS tracking | Expensive compared to basic trackers |
Fi Series 3+ Smart Collar Pros And Cons
Fi Collar Pros
Live GPS tracking
The Fi collar uses live GPS tracking via Wi-Fi and cellular service to let pet parents see their dog’s location in the Fi app.
If you live on a property with a lot of land where your dog has ample space to roam, you have your dog’s location at your fingertips through the app.
Of course, if you’re familiar with a GPS dog collar, you’ll know that live GPS tracking isn’t a particularly unique feature.
Any good smart dog collar should offer live GPS tracking, but I was impressed with the accuracy and reliability of the Fi smart dog collar during three years of use.
The Fi Series 3+ uses AT&T’s network. So it’s worth checking their coverage in your area to avoid any issues before purchasing.
Lost dog mode
As I touched upon in my Fi dog collar introduction, I wanted a smart dog collar that could provide support if a dog went missing.
If your dog is lost, Fi advises activating Live Tracking/Lost Dog Mode, which will prompt the Fi collar to look for either a live signal for Live Tracking or will attempt to look for a signal every minute for Original Lost Dog Mode.
I recommend testing the lost dog mode once you get your collar, because GPS & LTE coverage can vary depending on where you are. In my case, I had no issues.
By using the lost dog mode before disaster strikes, you can familiarize yourself with what lost dog mode looks like on the Fi app in the event that you do need to use it.
Safe zones
If you’re familiar with smart collars, you’ll probably have heard the term ”safe zones”. These allow dog parents to set up areas of their home, yard or property where their dog can safely roam.
If your dog’s location changes and they leave the safe zone, you’ll get a notification. You’ll need to make sure you’ve got escape alerts toggled on.
You can check the Fi app to see where your dog has gone or activate lost dog mode if required.
Having reviewed several smart dog collars, I want to emphasize that Fi doesn’t offer the same containment features as SpotOn or Halo. It works well if they leave a safe zone, but it won’t keep your dog in a space.
How does SpotOn compare to Fi Series 3+?
Discover my answer here.
Longer battery life
Fi states on its website that the Fi smart dog collar can last up to 3 months on a single charge.
I’ve been using the Fi dog collar for six months, and I went through my emails to see how many times the Fi app has sent me a notification that Skye’s Fi dog collar is at 5% or less.
Fi app had messaged me three times about battery life in the past six months, so I’ve been charging Skye’s Fi dog collar once every two months. I consider the impressive battery life compared to other smart collars we’ve previously used.
Sleep tracking
The Fi smart dog collar allows pet owners to track their dog’s sleeping patterns. The Fi collar keeps close tabs on how much your dog sleeps, the quality of their sleep, and much more.
Within the Fi app, you can see how a dog’s sleep-tracking stats are based on hours, days, weeks and months. If you’ve got multiple dogs, you can see their individual sleep tracking stats.
When I had the Sleep tab open in the Fi app, I could see the sleep tracking for Copper and Skye. Copper sleeps on average 10.8hrs a night and 7hrs a day. Skye, on the other hand, sleeps 13hrs a night and 6.5hrs a day. So sleep tracking shows Skye sleeps more per day!
Activity tracking
You’d expect dog trackers to offer activity tracking, and the Fi dog tracker is no different. The Fi collar offers stats based upon your dog’s daily steps, miles walked and how your dog’s stats compare to similar dogs and all dogs.
I really liked how Fi’s dog collar offers this feature. It made me realize I need to find more time for longer walks!
You can head to the activity tab in the Fi app to view your dog’s activity tracking. I could see Skye averages 231,000 steps a week and 10 miles a week. Copper racked up 373,000 steps and 9.4 miles a week.
Integrated design
In the UK, we previously used Tractive, but Copper and Skye always looked a little uncomfortable wearing the GPS tracker. The GPS tracker had a clunky design that seemed to weigh down my little dogs. Not only that, but the GPS tracker was an eyesore.
The Fi Series 3+ collar’s integrated design really caught my eye. The Fi collar band comes in four colors, and you attach the Fi device to your dog’s collar to provide a streamlined GPS collar, unlike some competitors’.
Copper and Skye looked much more comfortable wearing the Fi smart dog collar. Once we had Fi device attached, we never took the Fi smart collar off. That’s different from the Tractive that we were constantly removing.
However, I will say the Fi Mini worked even better, with a smaller and lighter design.
Waterproof
Since we lived in the UK for a long time, we always check whether a dog tracker is waterproof.
The Fi dog collar is waterproof, so if you’ve got a dog who likes to go for a dip, or you live in a location that rains a lot, or if you’ve got a toddler who likes to throw things down the loo, you don’t have to worry about your Fi collar getting wet.
Fi Dog Community
There’s a social element to Fi dogs that allows you to connect with other Fi dogs in a social setting.
Once we got our Fi dog collar series 3+, we could see how Copper and Skye’s activity compares to other dogs in our area, in our state and in the county as a whole.
Within the Fi app, you can easily see how your dog ranks by hitting the Rank tab.
It was quite the thrill to see an Alaskan Klee Kai leaderboard as a long-time Klee Kai owner. Unfortunately, we have work to do to get the top of it in 2026!
Fi Collar Cons
My dogs preferred the Fi Mini
I had the opportunity to test the Fi Mini against the Fi Series 3+ in 2026 – and there was a clear winner with my dogs.
Skye preferred wearing the Fi Mini because it’s lighter and less bulky. It was easy to attach to a regular collar, which I like because you don’t need a Fi collar.
There is no difference in battery life if you charge the Fi Mini using a Fi charging base. I found that the Fi Mini held battery longer than the Fi Series 3+.
All the tracking features are the same. They use different networks, though. The Mini uses Verizon, and the Series 3+ uses AT&T.
You can read my in-depth comparison article comparing the Mini and the Series 3+ here.
Fi subscription
The Fi Series 3+ only works with an active Fi subscription within the Fi app.
If you’re looking for a new collar and you’ve decided the Fi dog collar is for you, keep in mind that you’ll need a Fi subscription.
There are lots of options – monthly memberships, semi-annual plans, annual subscriptions and biannual options.
You’ll need to commit to a minimum six-month Fi subscription service before you can cancel. You can check out the current prices in the table below.
| Length | Price |
|---|---|
| 1 month trial | Free |
| 6 months | $99 ($3.80 per week) |
| 12 months | $189 ($3.60 per week) |
| 24 months | $339 ($3.20 per week) |
Multiple dogs
If you do decide to get a Fi collar and you’ve got multiple dogs, you’ll need a Fi collar series subscription for both dogs. As far as I’m aware, there’s no discount for multiple dogs, which is slightly disappointing.
For current Fi users who add another dog, I’d like to see Fi offer a discount for existing members of their community.
Fi Dog Collar Cost
There’s little doubt that the Fi dog collar is a premium smart collar that requires a significant upfront investment from dog parents.
If you’re looking for a smart dog collar, you’re paying for lost-dog mode, long-lasting battery life, GPS, a sleep tracker and more.
Do you want to take a deeper dive into cost?
You can read my full breakdopwn here.
But there are more affordable options if you want a GPS collar.
Just four colors
The Fi dog tracker comes in four colors for the Fi series 3+: yellow, blue, gray and pink. It’s a limited range, and I’d like to see more options for the Fi collar.
However, independent vendors create Fi-adapted collars in many colors to give pet owners more choice.
Is The Fi Series 3+ Collar Cost Worth It?
Continuing on from my previous point, it’s not until you have an experience like I had with Copper and his pursuit of the coyote that you appreciate the importance of having a reliable GPS tracker on your dog.
In those hellish five minutes, I was already bracing myself to tell my wife that I lost Copper and our Alaskan Klee Kai pack had been reduced to one. When Copper returned, I swore I would take more precautions.
The Fi Series 3+ collar and subscription are expensive. However, we signed up for their biannual plan to make the biggest savings possible. We paid $339 for the Fi Series 3+ collar and a two-year membership. That works out at $3.20 a week.
It’s important to remember that every Fi collar requires a $20 activation fee.
It’s been worth the investment because of the peace of mind that the Fi Series 3+ has provided Yasmin and I.
Copper has escaped our fenced yard twice in the past three years, and each time Fi alerted me that he had left the safe zone.
Fortunately, we were able to get him back inside our yard quickly on both occasions, and it was great to know that the Fi collar worked.
In my experience, the Fi Series 3+ was worth the price, but I acknowledge it’s a pricy smart dog collar.
Reasons To Buy The Fi Series 3+ And Reasons To Avoid
Who Should Buy The Fi Series 3+?
- Dog owners who want a tracking device integrated into the collar
- People who hike or travel with their dog and want a durable device
- Owners who value long battery life and a charger that’s simple to use
- Pet parents who want accurate tracking and reliable alerts
Who Should Skip It?
- Owners who prefer to avoid a subscription
- Dog owners with a yard who require a virtual fence
- Very small dogs that would be better served by the Fi Mini
- Pet owners who want containment features
Best Fi Series 3+ Smart Collar Alternatives
| Collar | Best Alternative For |
|---|---|
| SpotOn | Effective containment |
| Tractive | Cheaper subscription |
| Satellai | Activity monitoring |
| Fi Mini | Size and weight |
| Fi Series 3+ | Durability and battery life |
| Halo | Virtual fences |
Fi Series 3+ Collar FAQ
Yes I still believe the Fi Series 3+ is a worthwhile investment if you’ve got a medium or large dog and you want accurate tracking.
Yes you require an active subscription to use the Fi Series 3+ collar and the associated features.
I find the Fi Series 3+ GPS tracking to be accurate over my three years of use. However, I tend to walk my dogs in my neighborhood, where AT&T has good coverage.
Fi states on their website that it should last three months, but I’ve found it to be more like 2-3 months before requiring a charge.
The Fi Series 3+ is the newer version of the Fi Series 3. It includes improvements to tracking performance and additional smart features, but the overall experience is very similar. Much of my long-term experience with the Series 3 also applies to the current Series 3+.
The biggest difference between the Fi Series 3+ and Fi Mini is the size and weight. The Fi Series 3+ has a better battery life but this is negated if you charge your Fi Mini using the Fi base charger rather than a USB-C.
Wrapping Up
We’ve reached the end of our Fi Series 3+ smart dog collar pros and cons.
Having bought two dog collars and used the Fi Series 3+ over the past six months, I’ve discovered some of the advantages and disadvantages of the Fi Series.
They’ve also introduced the Fi Mini, which provides dog owners with a smaller, lighter option that may appeal to those with small dogs.
While Skye now wears the Fi Mini, I’m still using the Fi Series 3+ collar with Copper, because he’s the more active and adventurours of my two pups.
Overall, I believe the Fi Series 3+ smart dog collar is worth the investment considering the peace of mind it’s provided my wife and I that our dogs are safe.
With an incredibly long-lasting battery life, activity tracking, lost dog mode, sleep tracking and more, the Fi Series+ is a versatile smart dog collar with more pros than cons.
Kieran Beckles is an NCTJ-qualified journalist, a former pet nutrition student, and co-founder of Life With Klee Kai. He has been reviewing pet food and products since 2018, testing over 50+ brands, and has raised his dogs, Skye and Copper, since 2017. His work blends hands-on testing and nutrition knowledge to help pet owners make informed decisions.