How we test smartwatches & fitness trackers

Lifetime score

Our overall score combines test performance (how well the product works) with predicted reliability (how likely models from the brand are to remain free of faults) and brand satisfaction (how likely owners of the brand are to be satisfied).

Test performance

It’s no good if a product lasts for many years if it doesn’t work well in the first place. A disappointing product will soon become unloved and unwanted. For this reason, our independent lab testing forms an important part of our overall lifetime score.

Our smartwatches & fitness trackers test is based on:

• Fitness tracking

• Smart functions

• Ease of use

• Battery performance

• App

• Features

• Build quality

• Security and privacy.

Fitness tracking

• Step counter: We record the steps taken on a 10-minute walk, a 10-minute run, and while performing a range of household activities, including unloading a dishwasher and sweeping a floor. We compare the results to a calibrated pedometer to determine accuracy and consistency.

• Distance tracker: We walk and run routes through various terrain, and assess how close the device gets to the true distance.

• Heart rate: We measure the heart rate of our testers during low- and high-intensity exercise, and while at rest. We compare the results against a calibrated heart rate device that uses electrical signals.

We also assess the altimeter and elevation tracker, where available.

Smart functions

• Functionality: We check whether the watch alerts the user to incoming calls, emails and messages, and whether it can respond to or initiate phone calls and messages.

• Smartphone control: We examine if the watch can be used to control the connected phone’s functions, including the camera and music player.

Ease of use

An assessment by three people of the ease of set-up and everyday use, including while exercising. Ease of use includes ratings on the readability of the display in various lightings and how easy it is to navigate the menus.

Battery performance

• Battery life: We test how long a fully charged battery lasts under simulated day-and-night usage tests, including receiving phone calls and messages.

• Recharge time: We measure the time taken for the device to charge from 0% to 100%. Additionally, we record how much battery is gained from the first 30 minutes of charging.

App

Assesses the usability, functionality and features of the smartphone app on both Android and iOS, as well as its sync speed and the interface on the watch.

Features

Assesses the breadth of features available, including fitness and smart functions. We also look at how well you can customise the watch to your preferences, and how compatible it is with third-party apps.

Build quality

We scrutinise the quality of the material used in the watch and its strap or band, and note whether the band is replaceable. Additionally, we test scratch resistance by attempting to scratch it with a set pressure.

Security and privacy

We evaluate how well the watch encrypts information and protects against man-in-the-middle attacks, and whether resetting the device deletes all of your data. We also record how secure the password rules are and the level of support the watch gets from updates.

Predicted reliability

It’s reasonable to expect a new smartwatch or fitness tracker to remain fault-free for a good amount of time. Our predicted reliability won't tell you whether yours will stop working tomorrow, but it does show which brands make models that are less likely to fail early.

Brand satisfaction

Satisfaction is important – no product should be a source of buyer regret. Smartwatches & fitness trackers with satisfied owners are more likely to be taken care of and therefore last longer.

Survey data

In our reliability and satisfaction surveys, consumers tell us about faults that have left a product they own unusable or mean they’ve had to change how they use it. We also ask them how satisfied they are with the product. We use their data to produce our predicted reliability and brand satisfaction scores.

We use a statistical test to rate the relative performance of each brand. Compared to data we have for all products of the same type in the survey, we rate each brand with highest, high, average, low or lowest for reliability and satisfaction, respectively. You can compare the rating of different brands for the same product type (for example, the reliability rating of Apple and Samsung smartwatches), but you can’t compare the results for different product types (for example, satisfaction of Garmin smartwatches and Apple speakers).

We analyse brands that get at least 30 responses in our survey. That means there are some brands we can’t analyse because we don’t have enough data. For those brands, we assume they have average reliability and satisfaction.

Our data is based on 1,943 responses from owners of smartwatches & fitness trackers in our 2025 consumer survey.