How we test smartwatches at ZDNET in 2024

We spend days and weeks working, sleeping, and participating in various activities while wearing a smartwatch find out which ones are best to recommend to you.
Written by Matthew Miller, Contributing Writer

This smartwatch survived a 15K Tough Mudder.

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With advanced features such as voice assistantscrash detection, call and text support, and long battery lives, modern smartwatches are far more than just an accessory. And thanks to powerful sensors and extensive app suites, they've become one of the most popular health and fitness trackers, too.

How do we test and evaluate these smartwatches at ZDNET? How well is the watch supported by a smartphone companion? What functions and features stand out for each smartwatch? Here's the full breakdown.

Also: The best smartwatches you can buy

In most instances, the smartwatches we evaluate here on ZDNET are purchased after being released to the public, so there is no urgency in trying to publish a review based on a short period with the watch. Watches also require at least a couple weeks of 24/7 wear to test battery life, health and wellness tracking, GPS positioning accuracy, heart rate sensor reliability, and various design features.

We have relationships with most smartwatch brands, so we can send questions about the watch as we evaluate it and seek clarification on the hardware, software, and other aspects. We also test a handful of third-party applications, but with thousands of apps available on most of these watches, your personal experiences will vary from our testing.

Apple Watch on wrist
Jason Hiner/ZDNET

Smartwatch performance also depends upon a person's body geometry, the fit of the band on the wrist, the specific smartphone that the watch connects with, cellular reception quality (for connected models), and more. We provide readers with our perspective from testing the watches with our large-size wrists and phones.

Price and battery life are factors in our recommendations but are less significant because most smartwatches only last for a day or two between charging, unless you are considering more fitness-focused smartwatches that have fewer third-party apps and battery life measured in days or weeks. Most modern smartwatches also range in the $300 to $500 range so there isn't a major price element to consider.

What makes a smartwatch ZDNET recommended? 

A smartwatch serves as a companion to a smartphone and rarely stands alone. Since we have excluded price and battery life above, the basis for whether a smartwatch is recommended or not is determined by five other factors. Your preference for these five factors might differ from ours, but we started wearing smartwatches more than 20 years ago (Fossil Wrist PDA powered by Palm OS) and have refined our testing and evaluation processes.

Also: Best Garmin watches

The five factors we evaluate, in order of importance, are core functionality and performance, build quality and durability, health and wellness, applications, and advanced features. The advanced features are aspects of the smartwatch that set it apart from competitors and may target specific types of users. 

How we test smartwatches in 2024

Google Pixel Watch 2
Matthew Miller/ZDNET

Core functionality and performance

To justify occupying a spot on your wrist, a smartwatch has to provide core functions reliably. If the smartwatch creates any friction in the user experience, it is unlikely to be embraced as a daily wearable. First and foremost, a watch should clearly show you the time with a quick glance. Smartwatches have evolved over the years with custom watch faces that match your outfit and/or your personality so each watch can stand apart from others with the same model. 

Some watches make the watch face even more capable, with various complications or widgets showing you glanceable information beyond the time and date.

One way that a smartwatch distinguishes itself from a standard watch is that it serves as a remote for your phone and provides an accessible means to triage your key notifications so that your phone can remain on the charger, in your pocket, or in your bag. The smartwatch lets you look quickly at notifications without fully removing you from your current activity.

Matthew Miller/ZDNET

These core functions must also work reliably, with the time and notifications appearing whenever the user needs to see them. If a smartwatch provides inconsistent performance, it will likely end up for sale or in a drawer. We don't need wearables demanding our attention unless they are perfectly in sync with the connected phone.

We connect smartwatches to various phones, connect them to cellular service, measure the consistency in receiving notifications, track the reliability of launching complications, and keep track of inconsistent behavior when we evaluate each watch.

Build quality and durability

Every smartwatch today has a level of water resistance that supports wearing your watch in most conditions, although not all of them support submergence in water for extended periods of time. The watch face is covered by strong glass that is resilient to scratching. The body of most watches is constructed of polymer fiber, aluminum, titanium, or stainless steel, and buttons are built for pressing and/or rotating to navigate the user interface.

Also: Best waterproof smartwatches

Default watch bands come with your original purchase, but most smartwatches support standard 20, 22, or 26 mm bands. Amazon has an almost unlimited selection of watch bands, so you can find a reliable band that will keep the watch mounted on your wrist even during strenuous activities. 

We document any screen scratches that appear, wear the watches in the rain and during physical activities, and test out various bands as part of our evaluation.

Health and wellness

One of the biggest improvements in smartwatch technology over the past few years has been the integration of advanced health and wellness features that previously were found in dedicated health devices. Some of these dedicated sports watches went the other way and have embraced the smartphone by integrating notifications, third-party applications, messaging, and more so that we now see the convergence of these technologies in the smartwatch.

Apple continues to aggressively move forward with integrating advanced health and wellness in the Apple Watch and recently demonstrated several new features coming soon in watchOS 11 that will challenge its competitors. Health and wellness tracking make perfect sense in a smartwatch as battery life improves and ecosystems are built that provide practical insights and guidance to help smartwatch users improve their health and wellness.

Matthew Miller/ZDNET

Smartwatches are no longer only used by casual athletes, but professional athletes are using them to help improve their performance as detailed sleep tracking, recovery metrics, and performance trends are accurately provided with a smartwatch that also serves as the first mobile device that is picked up in the morning.

Also: The best Apple Watches

Health and wellness testing is my favorite aspect of evaluating smartwatches since it helps motivate me to run, bike, hike, row, walk, sleep, and participate in activities in order to test the accuracy of the location tracking, the heart rate monitoring, and more. I pay for a subscription and use the DC Rainmaker Analyzer to compare data that I capture with various smartwatches.


In the early days of smartwatches, third-party applications were fairly limited. Today, Google, Samsung, Apple, Garmin, and others have embraced developers by extending smartphone applications to the watch form factor. Apple sets the bar with the number of applications available, the extensive features of the applications, and the interface optimized for the small screen.

Also: Best Android smartwatches

Google's applications have been revived with the focus of the partnership with Samsung on the Galaxy Watch platform, but there are still many gaps that become clear when you compare a Google Wear smartwatch to an Apple Watch.

When we test smartwatches, we have a core set of 10-15 applications that work well on a smartwatch, and we test out which watches these applications work with and how well those applications work. Currently, Google closely matches what is offered by Apple, but the depth of the functionality is lacking in many cases.

Advanced features

This last factor is often the most interesting part of my review process since it is where I explore what a smartwatch can do above and beyond the standard fare. Garmin stands alone with its fantastic LED flashlight capability that I use every single day. Apple's Watch Ultra 2 automatically launches a cool submerged water interface when you take your watch into the pool or lake to exercise. Some Samsung models have a rotating physical bezel where you can spin the dial around the watch bezel to quickly scroll through lists.

Matthew Miller/ZDNET

Other common advanced features include music controls, crash/incident detection and notification, navigation, hands-free voice assistance, and blood pressure monitoring (only on Samsung watches outside of the US). There are still many other possible features and functions to come on future watches so stay tuned as we continue to discover these advanced features and look to the future of hologram wearables.

I use provided reviewer guides and even crack open the manuals to try to find these advanced features on various smartwatches. I also check out reviews from others testing the watches to find advanced features. It is also helpful to dive into the many levels of settings in watches to discover advanced features. Today's smartwatches are engineering marvels, and you can spend days and weeks diving into all of the details, functions, and options found within them.

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