This is not your typical dog GPS tracker comparison article or review. I have been involved in lost pet recovery work since 2009, and, yes, I will recommend what I believe are the best dog GPS trackers on the market today. But there is no best tracker that I recommend for every dog.
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The best GPS tracker for your dog will depend on a number of factors including:
- Your dog: what size are they and what type of tracker and collar will work for them?
- Your dog's behavior: why are they likely to go missing and how easy will it be to catch them once located?
- Your behavior: how good are you at remembering to keep your tracker charged?
- Your budget: what can you afford? There is the cost of the tracker and an annual subscription fee.
- Your phone: does the tracker app get good reviews for your operating system?
- Your location: what cell coverage do you have where you live and travel with your dog?
Based on my research and discussions with other lost pet specialists, the best dog GPS trackers in the US are Fi, Tractive and Whistle. So I tested out all three. I have been using Fi Series 3 on my new dog for six months and I used Whistle (and formerly Tagg) on my last dog for many years. I've also used an older version of Tractive on my cats.
I tested Fi Series 3, Tractive Dog 6 and Whistle Go Explore 2.0. During my testing, Fi introduced a new collar, the Fi Series 3+, which has some new AI features, but most tracking features are similar to the Series 3. Right before I published this article, Whistle announced that it had been bought out by Tractive and they were discontinuing all Whistle trackers. If you currently have a Whistle tracker, you can receive a free Tractive device and pro-rated subscription if you request it before September 30, 2025. Learn more here.
Use this article to help determine what is probably the best tracker for you, but in the end you will need to test the tracker out. I will provide some testing instructions and results of my own tests at the end of this article. Fortunately, all three of these trackers should have a 30 day satisfaction guarantee return policy. Be aware that you may need to purchase the tracker directly from their site and be sure to check out their current return policy.
Last update on 2025-09-15 / Affiliate links / Images from Amazon Product Advertising API
Dog Size and GPS Tracker Design
To find the best GPS tracker for your dog, the first factors to consider are the size and design of the tracker. GPS trackers can be bulky so you want to make sure that you get one that isn't too big for your dog. However, larger trackers tend to have a longer battery life, which is one of the most important features of a GPS tracker.
Dog size and trackers available
Small Dogs
- 5 lbs and up. The only tracker advertised for really small dogs is the Whistle Switch. But the Tractive version for cats is advertised for 6.6 lbs and up.
- 10 lbs and up. Fi Series 3+ or Tractive Dog 6. Whistle Go Explore 2.0 is advertised as best for dogs 25 lbs and up, but the tracker is actually smaller and lighter than the Tractive Dog 6.
Medium Dogs
- If your dog is between 25 and 50 lbs, you can use most trackers available including Fi Series 3+, Whistle Go Explore 2.0, Whistle Switch and Tractive Dog 6.
Large Dogs
- If your dog is 50 lbs or larger, you have the largest selection of GPS trackers including Fi Series 3+, Whistle Go Explore 2.0, Whistle Switch (up to 75 lbs) and Tractive Dog 6.
- In addition, Tractive has two versions for dogs over 50 lbs: the Tractive Dog XL and Tractive Dog XL Adventure.
Extra Large Dogs
- XL dogs can use most trackers (see Large Dogs above) except Whistle Switch, which maxes out at 75 lbs.
Dog GPS tracker design and collars
Dog GPS collars generally come in two designs: those that are integrated into the collar, and those that will attach to most collars. In general, the integrated GPS collars like Fi and Whistle Switch are smaller and less bulky.
Australian Cattle Dog (35 lbs) wearing Fi 3 with medium collar.
The Fi Series 3 (and new 3+) is the lightest (around 1 oz.), smallest dog GPS tracker that I tested. It also had the longest battery life. The only thing I did not love about Fi is that the collar that comes with the tracker is very heavy duty. This is great for larger dogs, but it looked uncomfortably large on my small (35 lb) Australian Cattle Dog. However, I have since learned that other companies sell collars and harnesses that are compatible with Fi trackers.
The only other issue that I had with the Fi collar is that you have to make it quite snug or your dog could pull the collar off if they got really scared. Obviously this depends on the size and shape of your dog's head and neck. For a skittish dog, I would recommend walking the dog with a separate martingale collar or opting for a tracker that will attach to a martingale collar.
Australian Cattle Dog (35 lbs) wearing Tractive (front) and Whistle (left side) GPS trackers.
The Tractive Dog 6 (1.4 oz.) and Whistle Go Explore (1.3 oz.) are larger and bulkier than the Fi Series 3. These trackers can attach to most collars. If you have a favorite collar already, these may be the way to go. The only downside is that the tracker could get pulled off the collar if your dog wrestles with other dogs or runs loose through the woods. This did not seem common, but I saw a few complaints in reviews. In my testing, I preferred the design of the Whistle attachment which seemed more secure, but was also easy to remove for charging.
Waterproof rating and durability
Other factors to consider, depending on your dog, are the waterproof rating and durability of the tracker. All the trackers had the same level of waterproof rating (IPX8 for Whistle and IP68 for Tractive). Only the Fi 3+ had an IP68 +66K rating, which includes protection against high speed jets of water.
The Fi 3 (and 3+) trackers are made of a stainless steel case and band attachment. The Tractive Dog 6 and Tractive Dog XL Adventure advertise a "bite-proof" fiberglass casing. The Tractive Dog XL and Whistle trackers appear to be made of a hard plastic.
The Importance of Battery Life
Once you know what trackers will fit your dog, the most important factors to consider are:
- Battery life. How long does the battery typically last, and perhaps more important, how long does it last when in Lost Dog Mode?
- Connectivity. Does the tracker have good cell coverage where you live and travel with your dog?
- Accuracy. Does the tracker quickly connect and provide accurate locations of your dog, especially in Lost Dog Mode?
Long battery life is so important because if your dog ever really goes missing, you will need to turn on Lost Dog Mode (aka LIVE mode or Find My Pet). When in Lost Dog Mode the tracker will take more frequent locations and this will drain the battery very quickly, perhaps within hours and at most a couple of days.
Long battery life is most important if ...
Battery life is most important if your dog is skittish, has phobias, or is newly adopted because they can take longer to catch when they go missing. When a skittish or panicked dog goes missing, they often enter "survival mode" and are likely to run from everyone and not even respond to their owner's voice. If you understand lost dog behavior, you may be able to lure your dog to you with calming signals. But many skittish and/or newly adopted dogs need to be caught using surveillance technology and a humane trap (or enclosure trap). Trapping a skittish lost dog can take days or even weeks even if you know where your dog is located.
IMPORTANT! If you have a skittish dog or one with phobias (such as fear of loud noises), make sure that you understand lost dog behavior before your dog goes missing. If you use your GPS to find your lost dog and approach them directly or call to them, you are likely to scare them away. If you keep doing this, you will probably drain your dog's GPS battery without catching them. There is also the risk that you might scare them out of a safe area and into somewhere dangerous such as a busy road.
Some trackers, like Tractive, also have a sound locating feature. If you have a skittish lost dog, NEVER use the sound feature to try and locate your dog. This is likely to scare them and cause them to run away.
Some skittish or panicked dogs can be caught without a humane trap, but you need to know what you are doing. In particular, you may be able to use calming signals to get your lost dog to approach you. Learn more about lost dog behavior and calming signals here.
Once you have located your lost dog, turn off Lost Dog Mode to preserve battery life and try calming signals to get them to approach you. If this does not work, keep Lost Dog Mode off (unless your dog is in a dangerous area) to preserve battery life as long as possible. Contact a pet detective or other lost pet specialist as soon as possible for professional advice and/or on-site help to maximize the chance of catching your dog quickly.
Longer battery life is also helpful if you are someone who probably won't remember to charge the tracker regularly. I have had many calls about lost dogs and cats wearing GPS trackers that weren't charged when the pet went missing.
Long battery life is less important if ...
If your dog is easy to catch once located, then battery life is somewhat less important. These are usually confident, friendly or even aloof dogs. These dogs are more likely to go missing because they get out of the yard to explore or they take off after wildlife while on a hike. Most important, they are off having a good time and aren't scared.
That said, even an otherwise friendly, confident dog may go into survival mode if they experience a traumatic event. For example, if they are attacked by another dog or are in a car accident.
Types of battery life to consider
Whether you decide to try one of the dog GPS trackers that I recommend or another tracker you find on the internet, make sure to check the stated battery life. There are numerous factors that impact battery life so there's no definite answer. Most trackers will state a battery life up to a certain number of days, weeks or months. This may indicate estimated typical battery life or maximum battery life.
- Maximum battery life. Most trackers use Wi-Fi when at home and allow you to set up one or more Safe Zones. If your dog primarily stays within Wi-Fi range, the tracker battery will last the longest because it is not using power to connect to satellites or send cellular data.
- Typical battery life. This will be unique to your dog and depend on how active they are, where you live, and the amount of time spent outside their Safe Zone. In particular, if you spend a lot of time traveling away from home, your average battery life will be a lot lower. Once you get your tracker, you should keep track of how long the battery tends to last for your dog.
- Battery life in Lost Dog Mode. When set to Lost Dog Mode (aka LIVE Mode or Find My Pet), the tracker will increase the frequency of location updates. This will drain the battery much more quickly.
Other factors that can impact battery life include cellular coverage, GPS availability, and temperature. Poor cell coverage will use more battery. The GPS connects most easily outdoors and under a clear sky. If your dog is indoors (and not in a Safe Zone), the tracker will use more power trying to connect to GPS. In general batteries drain more quickly in very cold or hot temperatures.
Battery Life Comparison
GPS Tracker | Stated Battery Life | Battery Life While Traveling* |
|---|---|---|
Fi 3 and 3+ | up to 3 months | 1-3 weeks |
Whistle Go Explore 2.0 | 15 days | could not find |
Whistle Switch | average 15 days | could not find |
Tractive Cat | up to 7 days | 2 days |
Tractive Dog 6 | up to 14 days | up to 6 days |
Tractive Dog XL | up to 1 month | 5-15 days |
Tractive Dog XL Adventure | up to 1 month | 5-15 days |
Table 1: Battery life comparison for Fi, Whistle and Tractive GPS trackers. *While Traveling means away from the base station, Wi-Fi and/or Safe Zones.
Most companies did not want to state or speculate on battery life in Lost Dog Mode. This is unfortunate since this is arguably the most important number. Fi 3 has an estimated battery life of up to 2 days when in Lost Dog Mode on a fully charged device.
Battery Life Testing Results
I tested typical battery life for the Fi Series 3, Whistle Go Explore 2.0 and Tractive Dog 6. Keep in mind that my test is only really accurate for my location (Pioneer Valley of western Massachusetts), my dog's activity, my traveling, and my phone (Samsung Android on AT&T).
Figure 1: Battery life test of Fi 3, Whistle Go Explore 2.0 and Tractive Dog 6 at home.
A few notes on my testing. The first day I was away from home for 12+ hours. The drop in battery life on 5/28, 29 and 31 was due to increased testing of Lost Dog Mode. All other days, my dog was at home and included 2 to 4 hours away from home each day. Whistle was set to Standard Location Alert Frequency.
I conducted one battery life test for Fi 3 and Tractive Dog 6 while on a five day camping trip. When traveling, you should expect more variability in battery life. The battery will drain more quickly if you are driving, your dog is very active or you are in an area with poor cell service.
Figure 2: Battery life test of Fi 3 and Tractive Dog 6 while camping.
A few notes on my testing. On the first and last day I was driving for 1 to 1.5 hours. I was camping in an area with good cell reception. I didn't do any Lost Dog Mode testing so this is just default tracking mode drain on the battery when away from home. Tractive drained pretty consistently around 19% per day. Fi averaged 12% drain per day, but had more variability. Fi only drained around 8% on days at the campground, but the battery dropped 11 to 20% on days with driving.
These charts are most useful as a comparison in battery life between the GPS trackers, but even that may be different for you depending on where you live. In particular, cell service could have a big impact on battery life. Fi and Whistle rely on AT&T while Tractive uses AT&T, Verizon and T-Mobile LTE networks in the US.
I am still testing how quickly the battery will drain in Lost Dog Mode. I will update this article after more testing.
Battery Life Testing Suggestions
Once you get a tracker, you should keep track of your average battery life. Compare your results to the Battery Life Comparison Table (1). Also if possible, try taking your dog to any areas farther from home that you occasionally visit. See how quickly your battery drains on these trips. Lastly, try running Lost Dog Mode for at least 15 to 30 minutes somewhere that you regularly take your dog. How quickly does the battery drain? You can do this while walking your dog if you turn off Bluetooth on your phone.
Personally, I would only suggest completely draining the battery once. After that, you can do most battery tests to 50% power so you don't risk having an empty tracker if your dog actually goes missing. In fact, I would recommend charging your tracker at 50% power or even more frequently as a general rule. It's great that some trackers will last for weeks before needing to be charged, but the battery will drain very quickly if you have to use Lost Dog Mode for any length of time. It's best to be prepared and have a charged battery, especially if you have a skittish or newly adopted dog.
Best Dog GPS Trackers for Battery Life
The Fi Series 3 and new 3+ have by far the best battery life. However, if you have a large dog over 50 lbs, the Tractive Dog XL and XL Adventure also have relatively long battery life.
Use this Referral Link to receive $20 off a Fi Series 3+ GPS collar and 1 month of free Fi Membership!
Last update on 2025-09-16 / Affiliate links / Images from Amazon Product Advertising API
Cost of Dog GPS Trackers
With most GPS trackers, you need to purchase the tracker and then purchase a subscription plan. One exception is Fi, which has you purchase a membership plan and the collar is included. Overall, Tractive GPS trackers tend to be cheaper, and often have discount codes and sales. Tractive also has the largest variety of plans available.
Costs, of course, are subject to change, but here's a comparison of costs from June 2025 from the companies' websites. You may be able to get a lower annual cost by purchasing several years in advance. Only Fi offered a six month plan.
GPS Tracker | Cost of Tracker | Cost of Annual Subscription | Total First Year* |
|---|---|---|---|
Fi 3+ | free with initial subscription | $189 | $189 |
Whistle Go Explore 2.0 | $129 | $99 | $228 |
Whistle Switch | $149 | $99 | $248 |
Tractive Cat | $49 | $108 - $120 | $157 - 169 |
Tractive Dog 6 | $69 | $108 - $120 | $177 - 189 |
Tractive Dog XL | $69 | $108 - $120 | $177 - 189 |
Tractive Dog XL Adventure | $99 | $108 - $120 | $207 - 219 |
Table 2: Cost comparison of Fi, Whistle and Tractive GPS trackers. *The total for the first year includes the cost of the tracker and a one year subscription. After the first year, you will only need to pay for the subscription until your tracker breaks, gets lost or you want to upgrade. Fi offered me an upgrade to the Fi Series 3+ for $99.
When considering costs, you may also want to check the company's current warranty. How long is it and what does it cover? As of June 2025, Fi was offering a lifetime warranty with active membership. Whistle only offered a six month warranty, and Tractive offered a two year warranty. In addition they also offered Tractive Care for $24 annually, which may provide you with a free or discounted tracker if yours is lost, damaged or stolen.
Check the Ratings of the Tracker App
Most dog GPS trackers work with an app on your cell phone. Before selecting a tracker, take a quick look at the app ratings for your phone operating system. I had a lot of issues while testing the Whistle Go Explore 2.0. It's likely this was partly due to the Whistle app that I was using. I have an Android phone and in Google Play, the Whistle app only had 2.1 stars, but it had 4.6 stars in the Apple App Store.
Will the Tracker Work Where You Live and Travel?
The last factor to check before purchasing a dog GPS tracker is whether it is likely to work where you live and travel with your dog. Dog GPS trackers work by getting a location via satellites and then sending that location to your cell phone app using cellular data and/or Bluetooth. In order to receive that location, both the GPS tracker and your phone need cell coverage. Your phone can also work via Wi-Fi, but this will make tracking your dog much more difficult since you will need to stay in the Wi-Fi zone.
Fi and Whistle both use AT&T's LTE-M network. The LTE-M network is a low-power, long-distance cellular network that reaches farther than conventional networks like 3G, 4G, 5G, and LTE. Fi only works in the US (including Puerto Rico and the USVI according to their support page). Whistle only works in the US and possibly parts of Canada with good AT&T coverage. You can check AT&T's coverage map here.
Tractive uses AT&T, Verizon and T-Mobile LTE networks in the US. Tractive is also the one popular US tracker that works in many other countries. With over 500 partners around the world, their trackers can connect to 2G and/or LTE (CatM1) cell networks in over 175 countries. You can check Tractive coverage at your address here.
IMPORTANT! If you live or primarily travel somewhere without cell phone reception, the dog GPS trackers discussed here will not work. You will need to purchase a tracker that works without cellular service such as a Garmin Dog GPS system like this one. Alternatively, you could try a radio frequency (RF) tracker such as the Marco Polo Tracking System.
Last update on 2025-09-16 / Affiliate links / Images from Amazon Product Advertising API
Testing Tracker Connectivity and Accuracy
Once you have selected a dog GPS tracker based on design, battery life, cost, app ratings and cell coverage, you will need to buy and test the tracker. Fortunately, most trackers offer a 30-day satisfaction guarantee. Be sure to check out their current refund policy before purchasing. You may need to purchase directly from the company, and the 30 days may start at purchase or at activation.
Don't wait until your dog really goes missing to find out how well your tracker works! I tested out the Fi Series 3, Whistle Go Explore 2.0 and Tractive Dog 6. I'll share my experience, but how well your tracker works will really depend on where you live and travel.
Testing Safe Zone Alerts
Once you get your tracker, you should set up a Safe Zone (aka Power Saving Zone or Safe Place) right away. If your dog leaves this area, you will receive a notification on the tracker app. One important factor of a good GPS tracker is how quickly you get an alert that your dog has left their Safe Zone. This is also one way to get an idea of your connectivity.
Try taking your dog for a walk and record how long it takes before you get a notification that they have left their Safe Zone. Do this at least several times on different days to get an average. If you can't walk where you live, you can also drive, but the important factor to measure is time and not distance.
Results of my Safe Zone tests
I tested the Fi Series 3, Tractive Dog 6, and Whistle Go Explore 2.0. I live in an area with good cell phone coverage. Fi and Tractive were generally fastest around 2 minutes (median) with Whistle lagging a little behind at 4 minutes. However, in 2 of 13 tests (15%), Fi took over 10 minutes to send an alert.
GPS Tracker | Mean | Median | Range |
|---|---|---|---|
Fi 3 | 4 | 2 | 1 to 12 |
Tractive Dog 6 | 3 | 2 | 2 to 5 |
Whistle Go Explore 2.0 | 4 | 4 | 3 to 6 |
Table 3: Test of Safe Zone alerts for dog GPS trackers. Shows the number of minutes before a notification was received that the dog had left the Safe Zone.
The Whistle app allows you to change Location Alert Frequency between Frequent (escape alerts every 1 to 3 minutes), Standard (escape alerts every 3 to 6 minutes), and Saver (escape alerts every 6 to 12 minutes). During these tests, Whistle was set to Standard Location Alert Frequency. The more frequently locations are taken, the shorter the battery life.
Testing Connectivity
Next you want to check connectivity both near your home and at locations that you frequently travel with your dog. In order to test connectivity, you need to be outside, away from your Safe Zone, and more than 30 feet away from your dog (beyond Bluetooth range). If you don't have a helper to hold your dog, you can just test with the collar. Alternatively, you can temporarily disable Bluetooth on your phone, but the app needs to think that you and your dog are separated.
Once you are away from your dog (or just the GPS tracker), check the current location in the tracker app. If you are using Fi or Tractive, you will probably have an up-to-date location if there is any cellular coverage. Whistle updates locations less frequently so it may show an old location. Then turn on Lost Dog Mode (aka LIVE Mode or Find My Pet) and measure how long it takes the tracker to connect and the app to provide an updated location. This test can be done as part of the Lost Dog Mode test or you can end here. Be sure to turn off Lost Dog Mode when done so you don't drain the battery.
Fi also has a method to test GPS and LTE-M connectivity built into the app. For step-by-step instructions, check out their support page.
Tractive has a method to check network and GPS connection built into the tracker itself. For instructions for the Tractive Dog 6, check out their support page. There's also a link from their page for other Tractive models.
Results of my connectivity tests
I tested the Fi Series 3, Tractive Dog 6, and Whistle Go Explore 2.0. I live in an area with good cell phone coverage, but I also traveled to a few areas with spotty coverage.
GPS Tracker | Mean | Median | Range | Failures |
|---|---|---|---|---|
Fi 3 | 1:25 | 1:15 | 0:10 to 4:00 | 0 of 9 |
Tractive Dog 6 | 0:14 | 0:15 | 0:10 to 0:18 | 1 of 7 |
Whistle Go Explore 2.0 | 3:23 | 2:20 | 0:15 to 9:30 | 1 of 7 |
Table 4: Connectivity Test for dog GPS trackers. Number of minutes that it took the app to connect to the tracker and provide an updated location when Lost Dog Mode was turned on.
Tractive Dog 6 Test Results
The Tractive Dog 6 had by far the fastest connection speed with an average of 15 seconds. However, there was one test in rural Vermont with spotty cell coverage where it could not connect. It appears that Tractive will try to connect for about a minute before a pop up appears that states: "Connection Too Weak. Buildings or trees may be blocking coverage where your tracker is. Try again in a minute." I tried moving the tracker to another location that said my phone had service and was open to the sky, but it still would not connect.
Even though Tractive could not connect to Lost Dog Mode (called LIVE mode in Tractive), I was still getting some connection. Tractive accurately recorded our walk and other time spent in that area. So I could still get locations on my dog, but they were not updated as frequently. In default tracking mode, Tractive updates the location every 2 to 60 minutes depending on activity level of your dog. If your dog is moving, you will get more frequent updates. In Lost Dog Mode, Tractive updates locations every 2 to 3 seconds. You can learn more about the difference between Default Tracking and LIVE Mode here.
Tractive Dog 6 created an accurate track in an area with poor cell reception.
Fi Series 3 Test Results
The Fi Series 3 had a pretty consistent connection time of around 1 minute. The only time it took longer to connect to Lost Dog Mode was in a rural area of VT with spotty cell coverage. There it took 4 minutes to connect. Unlike Tractive, Fi will continue to attempt to connect to Lost Dog Mode for several minutes. If it cannot connect after 5 minutes, it gives you the option to cancel Lost Dog Mode.
Like Tractive, Fi also provided up-to-date locations in this area while in default tracking mode, but the walk recording was a little less accurate. When in default tracking mode, Fi updates locations around once every 5 minutes. In Lost Dog Mode, Fi provides "real-time" updates. I'm still testing this feature, but it seemed to provide location updates between 3 to 5 times per minute when moving depending on speed.
Fi 3 created a somewhat accurate track in an area with poor cell reception.
Whistle Go Explore 2.0 Test Results
The Whistle Go Explore 2.0 was more variable in connection time, but usually took several minutes (when set to Standard Location Alert Frequency). However, in one Lost Dog Test at home with good cell coverage, the Whistle never connected. This may have been an app failure because several hours later, the walk showed as recorded so it was connected, but was not sending notifications to the app. Due to overall poorer performance, I returned the Whistle prior to being able to test it in Vermont.
When in default tracking mode (vs. Lost Dog Mode), the Whistle Go Explore updated locations much less frequently. In multiple tests, Whistle took a location when my dog first left their Safe Zone, but then it didn't update a new location until I requested one manually. Therefore, I didn't have any tracking ability with Whistle unless it could connect in Lost Dog Mode.
It is possible that my infrequent location updates were an app failure. The Whistle app only had 2.1 stars in the Google app store when I tested it. I had Location Alert Frequency set to Standard, which should send location updates every 3 minutes. Therefore, I should have received location updates at least every 6 minutes according to their support page.
Testing Lost Dog Mode Speed and Accuracy
Finally, you should test your tracker in Lost Dog Mode to determine the speed and accuracy of locations once connected. Even if you have a well trained dog, I wouldn't recommend just releasing your dog in the woods and trying to find them. To find out how really accurate the GPS tracker is, you want to know exactly where your dog went and where the tracker app said that they went.
There are a few different ways to test out Lost Dog Mode. The best way is to have someone else walk your dog, put the tracker on their own dog or carry the tracker while you try to locate them. Then compare where they went with where the tracker recorded. Most important, how easy was it to find them? Fi provides step-by-step instructions on how to test Lost Dog Mode here. When testing with Tractive, you should set LIVE tracking duration to 30 or 60 minutes or it will turn off after 5 minutes (the default setting).
If you don't have someone to help you with the test, there are a few other options. Option 1: First turn off Bluetooth on your phone. Then turn on Lost Dog Mode, wait for it to connect and take your dog for a walk. After your walk, turn Lost Dog Mode off and check the Timeline (Fi) or History (Tractive) to see a recording of the walk. This will help you determine the accuracy and frequency of GPS locations. Fi provides step-by-step instructions on this method as well.
Option 2: Place the tracker somewhere where it won't be stolen (even in your car is okay), then test out Lost Dog Mode and see how accurate it is. This is a good way to test whether the tracker app accurately determines your location as well as the tracker's location. Because if you don't know where YOU are, it is really hard to find your dog.
The second option can also be used to test out the Bluetooth tracking feature, which is available on Tractive and Whistle. You have to be really close (usually within 30 feet) for Bluetooth to work, so this is most useful if your dog loses their tracker. Tractive also has a sound alert feature to help you pinpoint the location of a lost tracker.
Results of My Lost Dog Mode Tests
I tested the Fi Series 3, Tractive Dog 6, and Whistle Go Explore 2.0. These tests were conducted in areas with decent cell phone coverage.
Tractive Dog 6 Test Results
Tractive was the easiest to use and the most accurate. When using Lost Dog Mode (called LIVE mode in Tractive), the app shows your dog's location, your location and their path of travel. Tractive updates locations every 2-3 seconds in Lost Dog Mode so it provides a very detailed path of travel. The downside of course is that battery level drops quickly.
Once close, you can turn on Radar mode, which is the Bluetooth feature on Tractive. Since you have to be really close, Bluetooth probably isn't useful unless you are looking for a lost tracker. In this case, Tractive has the best features since Bluetooth will even work in the Safe Zone if your dog loses their tracker at home. There is also a sound feature on Tractive to help you pinpoint the location, but it's not very loud.
Tractive Dog 6 GPS track during Lost Dog Mode test.
Fi Series 3 Test Results
Fi 3 overall worked well, but was a little more difficult to navigate than Tractive and had some glitches. When in Lost Dog Mode, the Fi app shows your dog's location and your location, but it doesn't show their path of travel. During this test, my location did not update frequently, so it was difficult to tell where I was. However, Fi has the option to get directions in Google Maps. When I did this, my location was updated. This is a good backup option to check where you are, but your dog's location will not update when in Google Maps.
Fi 3 Lost Dog Mode test.
In the Fi app, your dog's path of travel is recorded under the Timeline, but you can't view it until you turn off Lost Dog Mode. The path of travel recorded by Fi during the Lost Dog Mode test was less accurate than Tractive. There were a few glitches where the location jumped around. Overall, I have found that Fi tracks are sometimes very accurate and other times have some inaccurate locations that cause the track to jump around.
Fi uses Bluetooth, but doesn't have a separate Bluetooth tracking feature like Tractive and Whistle. When you get close, your icon will appear attached to your dog's icon in the app. This can make locating them more difficult if they are hiding, but you could try switching to Google Maps for a (hopefully) more accurate location.
Fi 3 GPS track recorded during Lost Dog Mode test.
Whistle Go Explore 2.0 Test Results
Whistle Go Explore worked okay, but had some glitches too. When in Lost Dog Mode (called Find My Pet), the Whistle app shows your location, your dog's location and their path of travel. But Whistle didn't update locations as frequently as Tractive or Fi. As you can see in the following map, the locations are connected by straight lines. According to their support page, Whistle will give you a location update every 15 seconds, but I only received 6 updates in 18 minutes.
My location also updated infrequently, which made tracking difficult. I was able to orient myself by the bends in the road, but if I were searching in the woods this would be impossible.
When close to the tracker, Whistle automatically turns on Bluetooth tracking. But again, you have to be really close for this to work. At one time, I was within a few feet of the tracker and Bluetooth didn't turn on.
Whistle GPS track during Lost Dog Mode test
When I tried testing Lost Dog Mode in another location with good cell reception, my location on the map updated infrequently for all three trackers. It took up to 5 minutes of remaining in one location for the apps to update my location. I don't yet know if this is a common issue with the trackers or perhaps an issue with my phone. More testing is needed.
My Recommendations
If cost is not an issue, I definitely recommend the Fi GPS collar. I tested the Fi Series 3, but the Series 3+ is now available. Fi has by far the best battery life and was generally accurate. It provided location updates 3 to 5 times per minute in Lost Dog Mode and at least every 5 minutes in regular tracking mode. The tracker is integrated with the collar, but other companies sell Fi compatible collars and harnesses if you want more options.
Use this Referral Link to receive $20 off a Fi Series 3+ GPS collar and 1 month of free Fi Membership!
With the exception of battery life, the Tractive Dog 6 was a great tracker. If anything, it was more accurate and updated lost dog locations more frequently than the Fi 3. Tractive also updates locations every 2 to 60 minutes in default tracking mode, so you don't need to waste battery life using Lost Dog Mode unless you really need it. If you have a larger dog, I would probably recommend one of the Tractive Dog XL trackers for improved battery life (though I did not get to test these). The Tractive trackers are more budget friendly, frequently have sales, and have more options for subscription plans. Tractive is also the only tracker that works in countries other than the US.
If you have a skittish dog, I would recommend Fi over Tractive. When a skittish dog goes missing, they often go into "survival mode" and are likely to run from everyone and not even respond to their owner's voice. Many skittish, panicked and/or newly adopted dogs need to be caught using surveillance technology and a humane trap (or large enclosure trap). This can take days or even weeks even when you know the location of your lost dog. Long battery life is essential. That said, the Fi collar itself is not great for skittish dogs because they might pull out of it. I would recommend walking a skittish dog on a separate martingale collar or buy a Fi compatible martingale collar.
At this point, I can't really recommend the Whistle Go Explore 2.0. I used Whistle (and previously Tagg) with my last dog for many years. But while other trackers have significantly improved their performance, Whistle seems to have lagged behind. The quality of their website information and support is also subpar.
Some of the issues that I had included slow connection in Find My Pet mode or not connecting at all. Whistle also sent fewer location updates, so I had no tracking ability if I couldn't connect to Find My Pet mode. It is possible that some of the issues I had were due to using an Android phone. At the time I conducted these tests, the Whistle app had a 2.1 star rating for Android and a 4.6 star rating for iPhones.
Right before I published this article, Tractive announced that it had purchased Whistle and the Whistle platform and devices would stop working on August 31, 2025.
Sources and Notes
Fi product and support pages. Support pages were detailed and updated.
PC Magazine Review of the Fi Smart Dog Collar Series 3.
Tractive product and support pages. Support pages were detailed and updated. Some useful pages include:
Whistle product and support pages. I found it harder to find detailed specifications on the Whistle website. A lot of the support page information seemed outdated.
