Apple Watch Series 11 vs Garmin Fenix 8: Is the 2025 Model Worth the Change?
Apple Watch Series 11 or Garmin Fenix 8? We compare price, measured performance and real-world trade-offs to work out which is the better buy.
Priya Raghunathan
The short answer
Apple Watch Series 11 WR50, IP6X, Garmin Fenix 8 10ATM, dive to 40m — the same test, run the same way. Where they part company is who they suit: the Apple Watch Series 11 is the one to get if you are iPhone owners who want health tracking that might actually matter, the Garmin Fenix 8 if you are endurance athletes and anyone off-grid for days.
Price difference: The Apple Watch Series 11 undercuts the Garmin Fenix 8 by £500. That gap only matters if the extras below are ones you will actually use.
Specifications side by side
| Specification | Apple Watch Series 11 | Garmin Fenix 8 |
|---|---|---|
| Price | £399 | £899 |
| Our score | 4 / 5 | 5 / 5 |
| Display | 45mm LTPO OLED, 2000 nits | 47mm AMOLED |
| Chip | S10 SiP | — |
| Battery | 28h with always-on | 16 days mixed use |
| Sensors | ECG, SpO2, temperature | HR, SpO2, barometer, depth |
| Rating | WR50, IP6X | 10ATM, dive to 40m |
| GNSS | — | Multi-band GPS, GLONASS, Galileo |
How we tested
Every figure quoted above comes from the same protocol, run on every unit in this category. This one spent three weeks worn continuously, including overnight. Worn on the non-dominant wrist alongside a chest-strap heart rate monitor and a second reference watch, with all figures logged from the same sessions.
| What we measure | How |
|---|---|
| Heart rate accuracy | Beat-by-beat comparison against the chest strap across steady runs, intervals and weights. |
| GPS accuracy | The same 5km loop, twelve times, compared against a surveyed route. |
| Battery life | A fixed daily pattern — one hour of GPS exercise, always-on display, sleep tracking — run to empty. |
| Sleep tracking | Compared against a manual log of actual sleep and wake times over fourteen nights. |
| Durability | Worn through cooking, washing up and the gym, with no attempt to protect it. |
We deliberately do not report step counts, which every device on the market gets close enough that the differences are noise.
The honest caveat: Wrist-based heart rate is least accurate exactly where people care most — high-intensity intervals.
Where the Apple Watch Series 11 wins
- The first genuine battery improvement in three generations
- The best health sensor suite available
- Fast charging
It also has the edge on the intangibles: sleep apnoea notifications flagged a genuine issue for one of our testers.
Where the Garmin Fenix 8 wins
- Sixteen days of measured battery life
- The best GPS accuracy we have recorded
- Genuinely rugged construction
And in day-to-day use, it traced a wooded valley route within four metres of a surveyed track.
The trade-offs
Neither is flawless. The Apple Watch Series 11 has one clear weak point — iPhone only — and the Garmin Fenix 8 has its own: very expensive. Weigh those against how you actually work rather than against the spec sheet.
The value case
The Garmin Fenix 8 costs £500 more and scores 1 point higher — roughly £500 per point of difference. Whether that is good value depends on whether the extra buys you sixteen days of measured battery life, or only a number. In our testing it is the former, but only just.
If neither quite fits
Look at the Galaxy Watch 7 at £289 — it scored 4 out of 5 and suits Galaxy phone owners who want deep integration. If the budget will not stretch, the Fitbit Charge 6 at £139 is the cheapest option in this category we would still put our name to.
Living with each of them
On paper the gap looks like a specification difference; in use it is a habits difference. With the Apple Watch Series 11 the thing you adjust to is iPhone only, and you do adjust — within a week it stops registering. Its display (45mm LTPO OLED, 2000 nits) is the part you stop thinking about. The Garmin Fenix 8 asks for a different accommodation: very expensive, against a display of 47mm AMOLED that holds up better than the number suggests. Neither compromise is severe. They are simply different, and which one you would rather not think about is a more useful question than which is objectively smaller.
Which one ages better
The Apple Watch Series 11 is 1 year newer, which usually means 1 more year of security updates at the far end of ownership — the part of the decision nobody weighs at the till and everybody feels at year four. The other half of ageing is the weak point you already know about: iPhone only on one side, very expensive on the other. Weaknesses of that kind do not improve with firmware, so assume you are buying them for the life of the device and price the decision accordingly.
Our recommendation
For most people we would take the Garmin Fenix 8, which scored 5 out of 5 in our testing against 4 for the other. That said, a score is a summary, not a substitute for knowing what you need.
Buy the Apple Watch Series 11 for the first genuine battery improvement in three generations. Buy the Garmin Fenix 8 for sixteen days of measured battery life.
Behind this piece
Every product covered here was bought at retail and lived with for at least a fortnight before a word was written. Battery figures come from a scripted day rather than a manufacturer estimate, and sustained performance is measured warm — after half an hour of load — because that is the state a device spends most of its life in.
Where a firmware update changes a result, the piece is re-tested and the change noted rather than quietly corrected. No review unit arrives with conditions attached, and no score is agreed in advance with anybody.
Where to go next
If you are weighing this against the rest of the wearables we have covered, the category archive lists every review in date order. The closest comparisons we have published are Apple Watch Series 11 vs Oura Ring 4: Is the 2025 Model Worth the Change? and Apple Watch Series 11 vs Pixel Watch 3: Is the 2025 Model Worth the Change?.
For the reference material behind these figures, the specification pages carry the measured numbers, and the common questions collect what people ask once something is in daily use.
