The Galaxy Z Flip 4 (left), Galaxy Z Flip 5 (center) and Motorola Razr Plus (right)
Numi Prasarn/CNET
We test every phone in real-world scenarios, focusing on its features, design, performance, cameras, battery life and overall value. We document our findings in an initial review that is periodically updated when there are new software updates, or to compare it against new phones from competitors such as Apple, Samsung, Google and OnePlus. Below is our methodology for testing smartphones in general, which also applies to flip phones.
Photography
Photography is a major focus for most phones these days, so we take pictures and videos of various subjects in a variety of settings and lighting scenarios. We try out any new camera modes, such as Action mode that debuted with the iPhone 14 line, or the Unblur photo tool that launched with the Google Pixel 7 series.
Taking a photo with the Galaxy Z Flip 5.
Amy Kim/CNETBattery life
Battery testing is conducted in a variety of ways. We assess how long a phone lasts during a typical day of use and note how it performs during more focused sessions of video calls, media streaming and gaming. We also conduct a video playback test, as a simple, replicable measure of pure battery life, which isn’t always included in the initial review but sometimes added later in an update.
Performance measuring
We use benchmarking apps to measure each phone’s performance, alongside our own anecdotal experiences using the phone for our review. Of note are how graphics and animations look. Are they smooth? Or do they lag or stutter? We also look at how quickly the phone switches between horizontal and vertical orientations, and how fast the camera app opens and is ready to take a photo.
We perform processor-heavy tasks like editing photos, exporting videos and playing games. We evaluate whether a newer version of a particular phone includes enough features to make it worth upgrading from older models.
Read more: How we test phones