If you’re here looking to buy a Whistle GPS tracker, you can’t. The entire Whistle product line was discontinued on August 31, 2025, when Tractive acquired the brand from Mars Petcare. All Whistle devices stopped functioning, existing subscriptions ended, and the Whistle app is no longer supported.
This page originally reviewed the Whistle GO Explore and Whistle Switch. Instead of deleting it, we’ve updated it to explain what happened and where to go from here.
- Whistle was discontinued August 31, 2025 after Tractive acquired the brand from Mars Petcare
- All Whistle devices and subscriptions stopped working on that date with no migration path
- Tractive GPS DOG 6 is the closest replacement with 4G LTE, heart rate monitoring, and global coverage
- Fi Series 3 is the best alternative if you want a GPS smart collar instead of a collar attachment
- Existing Whistle owners should recycle their devices and switch to a current tracker
What Happened to Whistle
Whistle was founded in 2012 in San Francisco and built one of the first widely adopted GPS pet trackers. Mars Petcare (the company behind Pedigree and Royal Canin) acquired Whistle in 2016.
For years, Whistle’s GO Explore model was among the best-selling pet GPS trackers on Amazon. It combined GPS tracking with health monitoring features like licking and scratching detection, sleep tracking, and wellness scores. The Whistle Switch offered a modular 2-in-1 design.
In early 2025, Tractive announced it had acquired the Whistle brand. By August 31, 2025, all Whistle services were permanently shut down. Existing devices could not be transferred to Tractive’s platform. Whistle owners were offered a discount on Tractive hardware, but many felt the transition was handled poorly.
The practical impact: if you still have a Whistle tracker, it’s now a paperweight.
What Whistle Offered (for Reference)
Before discontinuation, Whistle GPS trackers provided:
- Real-time GPS tracking with 60-second location updates via AT&T’s cellular network
- Custom safe zones with escape alerts when pets left designated areas
- Activity and rest monitoring with daily goals and trend analysis
- Health monitoring including licking, scratching, sleep quality, and eating behavior patterns
- IP67 water resistance in a sub-1-ounce device
- Multi-pet support with family sharing access
The GO Explore cost $129 for hardware plus $7-10/month for subscription service. US-only coverage via AT&T.
These features set a high bar for pet trackers in 2020-2024. But by 2025, competitors had caught up or surpassed most of them.
Best Alternatives to Whistle in 2026
Tractive GPS DOG 6
The most direct replacement. Tractive acquired Whistle’s technology and now offers the most feature-rich pet GPS tracker on the market.
The DOG 6 tracks over 4G LTE in 150+ countries, which already beats Whistle’s US-only AT&T coverage. It adds heart rate monitoring and bark detection that Whistle never had. Battery lasts 2-5 days depending on tracking frequency. Subscriptions start at $5/month on annual plans.
For a full review, see our Tractive GPS pet tracker review.
Fi Series 3 Smart Dog Collar
If you want GPS built into the collar itself rather than an attachment, the Fi Series 3 is the leading option. It uses GPS + LTE with a battery that lasts up to 3 months in standard mode.
The Fi collar is heavier at 28g for the tracker module and requires buying their specific collar bands. But the battery life advantage over both Whistle and Tractive is massive. It starts at $149 for hardware plus $14-19/month.
For Cats
Whistle was always a dog-first product. If you had a Whistle and used it on a cat, the best GPS trackers for cats now include the Tractive CAT Mini at just 25g with the same 4G LTE global coverage. The Weenect Cat 2 is another option for European cat owners at 25g.
Whistle vs Current Alternatives
| Feature | Whistle GO Explore (discontinued) | Tractive DOG 6 | Fi Series 3 |
|---|---|---|---|
| Status | Discontinued | Available | Available |
| Network | AT&T (US only) | 4G LTE (150+ countries) | LTE (US, some international) |
| Battery | 5-10 days | 2-5 days | Up to 3 months |
| Health features | Licking, scratching, sleep | Heart rate, bark detection | Step tracking |
| Weight | ~1 oz | 35g | 28g (module) |
| Monthly cost | $7-10 | From $5 | $14-19 |
| Water resistance | IP67 | IP67 | IP68 |
Tractive matches or beats Whistle on most metrics except battery life. Fi wins on battery life but costs significantly more per month.
If You Still Have a Whistle Device
Your Whistle tracker no longer connects to any servers. Here’s what to do:
- Cancel any remaining subscription through your payment provider if auto-renewal is still active
- Recycle the device through your local e-waste program
- Choose a replacement from the alternatives above
- Export any data you want to keep from the Whistle app before it’s fully removed from app stores (if it hasn’t been already)
For a broader look at the best GPS trackers for pets currently available, or trackers with no monthly subscription fees, we have updated guides for both.
Bottom Line
Whistle was a pioneer in GPS pet tracking, but the brand is gone. If you’re shopping for a pet GPS tracker in 2026, the Tractive GPS DOG 6 is the most complete replacement with better global coverage and newer health monitoring features. Fi Series 3 is the premium alternative with exceptional battery life. Don’t buy any Whistle hardware secondhand, as it won’t activate.
FAQ
Why was Whistle discontinued?
Tractive acquired the Whistle brand from Mars Petcare in 2025 and chose to shut down all Whistle hardware and services rather than maintain a separate product line. All Whistle devices stopped working on August 31, 2025.
Can I still activate a new Whistle tracker?
No. Whistle's servers are permanently offline. Even a sealed, never-opened Whistle device cannot be activated. Do not purchase Whistle hardware from any source, as it will not function.
Did Whistle owners get compensation?
Tractive offered discounted hardware to former Whistle subscribers. However, many owners reported that the transition was poorly communicated and the discount did not fully offset the cost of switching. No refunds were issued for unused Whistle subscription time in most cases.
What is the best replacement for a Whistle GPS tracker?
The Tractive GPS DOG 6 is the closest feature match with 4G LTE coverage in 150+ countries, heart rate monitoring, and subscription plans starting at $5/month. For longer battery life, the Fi Series 3 smart collar lasts up to 3 months between charges.
Does the Tractive app work the same as the Whistle app?
The core features are similar: real-time GPS tracking, geofencing, activity monitoring. Tractive adds heart rate and bark detection. The interface is different, but most former Whistle users find the transition straightforward. Whistle's licking and scratching detection is not available in Tractive.
Can I use an AirTag instead of a pet GPS tracker?
AirTags use Bluetooth, not GPS. They rely on nearby iPhones to relay location, which works in populated areas but fails in parks, rural trails, and woods. For real-time pet tracking with cellular coverage, a dedicated GPS pet tracker is far more reliable. See our comparison of AirTag vs GPS trackers.
Are there pet GPS trackers that work without a subscription?
Very few GPS pet trackers work without monthly fees since cellular data is required for real-time tracking. Options exist but come with trade-offs. See our guide to pet GPS trackers without monthly fees for current options.