The iPhone 13 and Samsung S21 Ultra were both introduced in 2021. As such, they were destined to be subjected to technical comparisons. If you're looking for a high-end smartphone, you'll be happy to know you'd be happy with either device. That said, the two have some key differences you should consider. 

The performance of Apple devices isn't questioned anymore. The iPhone 13 is a testament to why, with its many features and high-end components. Consider its battery, which gives the phone about 15% more life than that of the Samsung Galaxy S21 Ultra. This smartphone is also lighter and more compact. It measures 146.7 x 71.5 x 7.7 mm and weighs 174 grams, where the Samsung S21 Ultra measures 165.1 x 75.6 x 8.9 mm for 227 grams. The iPhone 13 does loses its advantage in amount of RAM though. It is only 4 GB compared to 12 GB or even 16 GB for the Samsung S21 Ultra.

The Samsung S21 Ultra is larger and comes with a 6.8-inch screen (compared to 6.1 on the iPhone 13). On this point, it takes the advantage. Not only because of its larger size, but also because of the performance of its display. It boasts Dynamic AMOLED technology (OLED for the iPhone 13) with a refresh rate of 120 Hz, against only 60 Hz for the Apple smartphone. It therefore sees significant gains in fluidity.

Another major difference is its photographic performance. While the iPhone 13 offers a 12 MP camera, the Samsung S21 Ultra has a 108 MP sensor with a 10x optical zoom. This smartphone is also the only one of the two that allows dual SIM cards and has a fingerprint sensor.

These two recent smartphones are among the most premium at the moment. While there are some components that differentiate them, your choice is mostly based on the internal software of each device. Some users like Apple's iOS, others like the Android system found on the Samsung S21 Ultra.