The strange thing about fitness trackers in 2026 is how the £30 Mi Band has quietly closed the gap on the £150 Fitbit Charge for casual users. Both count steps competently. Both estimate sleep with similar reliability (which is to say: roughly, with caveats). Both monitor heart rate accurately enough for general fitness purposes. The Fitbit has a nicer app and better software polish. The Mi Band has 14 days of battery and saves you £100.
For UK adults who want activity, sleep, and heart rate tracking without committing to a full smartwatch, the Mi Band is the right answer most of the time. Fitbit earns its premium for users who'll engage with the Fitbit Premium app and want Google ecosystem integration. Whoop is a different category entirely — a serious athlete's recovery tool, not a casual tracker.
We tested four UK-popular fitness trackers across two months: Xiaomi Mi Band 9, Fitbit Charge 6, Garmin Vivosmart 5, and Whoop 5.0.
How to pick
Casual user, want core stats cheaply: Xiaomi Mi Band 9 at £30-£45.
Want Fitbit ecosystem / Premium features: Fitbit Charge 6 at £130-£160.
Want Garmin's training metrics: Garmin Vivosmart 5 at £130-£170.
Serious athlete, recovery focus: Whoop 5.0 at £24/month subscription.
For most casual users: Xiaomi Mi Band 9 at £35. Genuinely good value; covers steps, heart rate, sleep, basic exercise tracking.
The four worth knowing
Xiaomi Mi Band 9 at £30-£45. Mainstream fitness tracker. 14-day battery, AMOLED display, all the basic metrics, app integration with Apple Health and Google Fit, water resistant. Cheapest of the four by a substantial margin; covers core metrics; excellent battery; good integrations. App less polished than Fitbit; no GPS (uses phone); less retail presence in UK.
Fitbit Charge 6 at £130-£160. Fitbit's mainstream tracker. Tighter integration with Google ecosystem (Fitbit owned by Google since 2021). GPS built in. Solid app.
Garmin Vivosmart 5 at £130-£170. Garmin's slim fitness tracker. Less feature-rich than Garmin's Forerunner watches but with similar Garmin Connect ecosystem.
Whoop 5.0 at £24/month or £252/year. Different category — a subscription-locked recovery-focused tracker. The "device is free" model means you're committed to ongoing payment. For serious athletes, Whoop is genuinely useful — recovery scores predict bad-training days with measurable accuracy. For casual fitness users, Whoop is overkill and the subscription doesn't justify itself.
How I'd actually pick
Casual fitness users wanting basic tracking: Mi Band 9 at £35. Don't overpay.
UK adults wanting Fitbit ecosystem: Fitbit Charge 6.
Garmin users (already wear a Garmin watch sometimes): Vivosmart 5 as a daily-wear tracker complement.
Serious athletes: Whoop 5.0 if recovery insights drive your training.
What I'd swerve: paying £100-plus for fitness trackers from unknown brands; cheap (£10-£20) fitness trackers from supermarket brands (sensor accuracy poor).
For UK adults considering full smartwatches: see our wearables comparison covering Apple Watch, Whoop, Oura.
Affiliate disclosure: Morningfold has affiliate partnerships with Xiaomi, Fitbit, Garmin, Whoop. See editorial standards.