Tom’s Guide put nine smartphones through the same test, which has the phones constantly roaming the internet on 4G at 150 nits of screen brightness. The iPhone XS lasted 9 hours 41 minutes, while the iPhone XS Max stayed alive a little longer at 10h 38m.
The Android-powered phones that exceeded Apple smartphones included the OnePlus 6 (11:22), the Samsung Galaxy Note 9 (11:26), the Google Pixel 2 XL (12:09) and the the Huawei P20 Pro at an impressive 14h 13m.
More evidence to back up TechRadar's findings
That's along the lines of what TechRadar found in its iPhone XS and XS Max reviews. The battery life doesn't push the envelope, but it's solid enough for most people.
"The iPhone XS Max can last a day on a single charge with moderate to high usage," said Gareth Beavis. "This isn't a phone that will last you a day and a half to two days with moderate usage, but if you're less intensive then this is possible as on the lighter days we managed to head to bed with at least 30% of power remaining."
As for the iPhone XS, he noted, "We’re confident that the iPhone XS is one of Apple’s better performers on battery life, but it’s not going to trouble the top performers on the market."
Not underperforming, just below average
The iPhone XS didn't outrageously underperform in the Tom's Guide test, coming in seven minutes short of the category average score of 9h 48m. Likewise, the iPhone XS lasted 50 minutes longer the average.
A recent teardown of the iPhone XS and iPhone XS Max revealed a new singular, L-shaped 2,659-mAh battery in the smaller phone, and a dual-battery setup with a combined 3,179-mAh. Those aren’t as big as the Galaxy Note 9, for example, which has a 4,000-mAh battery (and reached 11:26 in this test).
Granted, this is a single, particular test, so different phones may have longer or shorter battery life doing different tasks. But it is a uniform benchmark to compare phones, especially between iOS and Android devices, and get a crude view of how long they’d last doing what we all spend a lot of time doing on our phones: cruising around the internet.