Buying guide· Health & Fitness Tech
Fitness tracker and smartwatch buying guide
Band, smartwatch or GPS watch? Compatibility, battery life, GPS, sensors, water resistance and subscriptions explained.
- HotWhatHow editorial team
- Last reviewed
- 4 min read
Fitness trackers and smartwatches count steps, record workouts, show notifications and, in many cases, track your location on runs and rides. The range runs from slim bands with week-long battery life to full smartwatches with apps and mobile payments. This guide explains the specifications that matter, how to choose between the main types and what to check before you buy. It is general product information; these devices are consumer gadgets, and nothing here is medical advice.
Band, smartwatch or sports watch?
Fitness band
A slim strap with a small screen. Bands are light, comfortable to wear overnight and often have a long battery life. They usually rely on a phone for GPS and have limited apps.
Smartwatch
A larger screen, notifications you can reply to, third-party apps, mobile payments and often a choice of watch faces. Battery life is usually shorter, sometimes a day or two. Many smartwatches work best, or only, with one phone system, so check compatibility.
Sports or GPS watch
Designed around training: built-in GPS, detailed workout data, physical buttons that work with gloves and wet hands, and long battery life in GPS mode. Some include maps for navigation.
Compatibility first
Before anything else, check that the device works with your phone. Some smartwatches only work with iPhone or only with Android. Look at the companion app as well: it is where your data lives, and some features may require a subscription. Check what is included free and what is paid.
The specs that matter
Battery life
Manufacturers usually quote battery life in typical use and separately with GPS on. If you record long activities, the GPS figure matters most. Always-on displays, frequent notifications and music playback reduce battery life.
GPS
Built-in GPS records your route without carrying a phone. "Connected GPS" uses your phone's GPS instead. Some devices support multiple satellite systems or dual-frequency GPS, which manufacturers describe as improving positioning in difficult areas such as cities and forests.
Sensors
Most devices include an optical heart-rate sensor and an accelerometer. Others add a barometric altimeter for elevation, a compass, a skin temperature sensor and more. Sensor readings are estimates from a consumer device; they are useful for spotting your own trends but are not medical measurements. Some devices offer features that have specific regulatory clearance in certain countries — the manufacturer's documentation explains what each feature is and is not intended for.
Display
AMOLED screens are bright and colourful; memory-in-pixel (transflective) screens are easier to read in sunlight and use less power. Check the screen size and whether it has an always-on mode.
Water resistance
Usually listed in ATM or metres, sometimes with a swim-proof rating. A rating suitable for swimming is not the same as one for diving. Check the manufacturer's guidance for the activities you plan.
Everyday features
- Smartphone notifications and whether you can reply.
- Contactless payments, and whether your bank is supported.
- Music storage or streaming-service control.
- Sleep tracking, presented as an estimate.
- Strap sizes and whether straps are standard and easy to replace.
Privacy and data
Fitness devices collect personal information. Read how the manufacturer stores your data, whether you can export or delete it, and which settings control sharing. Turning off features you do not use can also save battery.
Key specs explained
| Spec | What it tells you | What to look for |
|---|---|---|
| Compatibility | Which phones it works with | Works fully with your phone's operating system |
| Battery life | Typical use and GPS-mode figures | The figure for how you will use it |
| GPS | Built-in, connected or multi-band | Built-in if you run or ride without your phone |
| Sensors | Heart rate, altimeter, compass and more | The sensors you will use — readings are estimates |
| Display | AMOLED or memory-in-pixel, size, always-on | Readable where you use it |
| Water resistance | ATM rating or swim-proof label | Suitable for the activities you plan |
| Subscription | Paid features in the companion app | What is free and what costs extra |
| Payments / music | Contactless and music features | Only if you will use them |
Questions to ask before you buy
- Does it work fully with my phone?
- What is the battery life for the way I will use it?
- Do I need built-in GPS?
- Which features need a paid subscription?
- Is it comfortable to wear all day and overnight?
- How does the manufacturer handle my data, and can I export it?
Frequently asked questions
Are fitness tracker readings accurate?
They are estimates from consumer sensors. They are useful for following your own trends over time, but they are not medical devices. For any health concern, speak to a healthcare professional.
Do I need a smartwatch or is a band enough?
If you mainly want activity tracking, sleep estimates and long battery life, a band may be enough. If you want apps, payments, replies to messages or detailed GPS training, a smartwatch or sports watch suits you better.
Can I swim with a fitness tracker?
Many are suitable for swimming, but check the water resistance rating and the manufacturer's guidance. A rating suitable for swimming is not necessarily suitable for diving or high-pressure water.
Will it work if I change phones?
Some devices work with both iPhone and Android; others only work with one. Check compatibility before you change phones.
Prices & links
HotWhatHow compares live prices from retailers as they are connected to the site. When offers are available, we rank them by the total landed price — the item price plus standard delivery — and show when each price was last checked. Some retailer links are affiliate links; we may earn a commission, which never changes which offer we label as the cheapest. This guide is based on manufacturer specifications and general product information, not on our own use of the products, and it is not medical advice.
Written by the HotWhatHow editorial team with AI assistance, from manufacturer specifications and general product information. We do not test products ourselves, invent ratings or quote prices in guides.