US prices from official stores, checked on November 9, 2026 · 14 collars compared · no paid scores
Cost Calculator
Fi Series 3+, gps dog tracker

Images: Fi

Fi Series 3+ review

Fi · GPS dog tracker · No. 7 of 10 in our GPS collar ranking

8.3Good · out of 10

The tracker with the longest battery we compare, up to 3 months per charge, where the membership is the real price.

  • Up to 3 months between charges, the longest of any device we compare
  • IP68 waterproof and rated for 500+ lb of pull
  • Escape alerts only: it does not stop your dog at a boundary
$129

Fi official store, price checked on November 9, 2026. $657 over 3 years with the plan.

View offer at Fi ↗$129
Compare with its rivals ↗

Some links are affiliate links: we may earn a commission at no extra cost to you. It never changes our scores.

Specs
TypeGPS dog tracker
Device price$129 on November 9, 2026
PlanMembership required: $99 for 6 months, $189 a year or $339 for two years, with a 6-month minimum commitment.
3-year cost$657 (device + 36 months of plan at the cheapest published billing cycle)
ContainmentEscape alerts only: Safe zones with escape alerts (no cue to the dog)
PositioningSingle-frequency GNSS
Live trackingLive GPS over LTE-M, Lost Dog Mode, escape alerts
Boundary cuesNo correction: alerts go to your phone
BatteryUp to 3 months per charge
Neck sizeXS band for dogs under 10 lb (9.5-11 in) up to XL (20-31 in)
Water resistanceIP68 and IP66K, salt water tested
Warranty and returns1-year warranty; 30-day returns
AvailabilityIn stock at the official US store
In the box
  • Fi Series 3+ tracker
  • Colored collar
  • Fi Base (charger and signal enhancer)
Where to buy
Fi official store ↗$129

Some links are affiliate links: we may earn a commission at no extra cost to you. It never changes our scores. Affiliate disclosure

How we score

Same criteria and weights for every device: containment and the 3-year cost count most, and static correction never earns points.

Raw score (weighted average)6.3/10
Displayed score (editorial scale)8.3/10

Read the full methodology ↗

Price checked on November 9, 2026
$657 over 3 years, plan included
30-day return window

By Sam Rivera, the editorial team · Updated November 9, 2026

Compared with its rivals

The two alternatives we would look at next, with their 3-year cost.

Compare: side-by-side table ↗

Fi Series 3+

Fi Series 3+

8.3Good · out of 10
  • $657 over 3 years
  • Subscription: required, from $14.13/mo
  • Checked price: $129
This device ↑
Tractive DOG 6

Tractive DOG 6

8.6Very good · out of 10
  • $79 and 1.4 oz, cheaper over three years
  • $427 over 3 years
  • Subscription: required, from $6/mo
  • Checked price: $79
Read the review ↗
Halo Collar 4

Halo Collar 4

9.2Excellent · out of 10
  • Tracking plus a real fence, $424 plus a plan
  • $744 over 3 years
  • Subscription: required, from $8.74/mo
  • Checked price: $424
Read the review ↗

$657 over three years

$129 for the device plus $528 of Fi Membership over 36 months, at the cheapest published billing cycle.

Great if…

  • your yard is fenced and you want to know fast when your dog gets out
  • you hate charging
  • your dog is a strong puller or a swimmer

Skip it if…

  • you need to keep a dog in an unfenced yard: look at a GPS fence
  • you want the cheapest tracker: the Tractive DOG 6 costs about $427 over three years
  • you dislike a 6-month minimum commitment

What living with it looks like

Fi sells the tracker as part of a collar, in sizes from an XS band for dogs under 10 lb to XL. A Fi Base charges it and acts as a signal enhancer at home. Location comes over LTE-M; Lost Dog Mode speeds up updates when your dog is missing, and escape alerts tell you when it leaves a safe zone.

Up to 3 months per charge means you will forget where the charger is. Fi states IP68 and IP66K, salt-water tested.

By the numbers
3-year cost
$657
Subscription
From $14.13/mo
Device
$129

The catch

The membership is required: $99 for 6 months, $189 a year or $339 for two years, with a 6-month minimum. At the best combination of those cycles, three years of membership cost about $528.

Warranty is 1 year, returns 30 days. A 30% veterans code ran until November 12; codes are not counted in our price.

By the numbers
Battery
90 days

Buying advice

Checked at $129 on Fi's store on November 9, 2026, plus the membership.

View offer at Fi ↗3-year cost calculator
By the numbers
Checked price
$129
Warranty
1 year

The verdict

The Fi Series 3+ is the tracker with the longest battery we compare, up to 3 months per charge, in an IP68 collar rated for 500+ lb of pull. It scores 8.3/10. It is not a fence: safe zones send an alert to your phone, nothing cues your dog. And the membership is the real price, about $528 of the $657 three-year total.

View offer at Fi ↗All GPS dog fences ranked

How it compares

The Fi Series 3+ next to the two rivals above, from the official spec sheets and the US prices checked on November 9, 2026. Key spec = the 3-year cost.

Comparison tool
How the Fi Series 3+ compares with its rivals
Fi Series 3+Fi Series 3+Fi8.3$129$657 over 3 years · 90 daysPhone app over LTE1 year
Tractive DOG 6Tractive DOG 6Tractive8.6$79$427 over 3 years · 14 days · dogs 8.8 lb+Phone app over LTENot stated
Halo Collar 4Halo Collar 4Halo9.2$424$744 over 3 years · 40 h · dogs 10 lb+Phone app over LTE1 year

The score in detail

Fi Series 3+ gets 8.3/10 (good) with our overall weights, from a raw weighted average of 6.3/10. Left out because no figure is stated or the criterion does not apply: gentle boundary cues, fits small dogs, smallest yard. The scales are on the methodology page.

Containment

2.5/10

Weight: 26.7% of the overall score

3-year cost

6.8/10

Weight: 26.7% of the overall score

Live tracking

10.0/10

Weight: 13.3% of the overall score

Positioning hardware

6.0/10

Weight: 13.3% of the overall score

Battery life

10.0/10

Weight: 13.3% of the overall score

Warranty

5.0/10

Weight: 6.7% of the overall score

By use, with the same figures and other weights: best gps dog collar 8.8/10 (No. 7).

Frequently asked questions

Does Fi need a subscription?

Yes: $99 for 6 months, $189 a year or $339 for two years, with a 6-month minimum commitment.

Fi or Tractive?

Tractive is cheaper and lighter; Fi lasts much longer per charge and comes as a sturdy collar. See Tractive vs Fi.

Go further

Head-to-heads with this collar

Tractive DOG 6 vs Fi Series 3+ →Halo Collar 5 vs Fi Series 3+ →Compare with two rivals →

Rankings it appears in

Best GPS dog collar →

Guides that mention it

Subscription costs →AirTag vs GPS tracker →3-year cost calculator →

Sources

Official pages read on November 9, 2026: shop.fitracking.com/shop?selected=s3&products=s3 · support.fitracking.com/hc/en-us/articles/7048727038995-Fi-Membership-Billing · support.fitracking.com/hc/en-us/articles/360018860034-Find-Your-Fi-Series-Collar-Size · fitracking.com/collar. Product images: Fi.

All GPS dog fences ranked ↗All reviewsAll head-to-headsComparison tool