Which SIM card format is most commonly used in modern smartphones?

The most commonly used SIM card format in modern smartphones is the Nano-SIM. This format was introduced to reduce the physical size of the SIM card, allowing for more space within the smartphone for other components such as a larger battery or improved hardware. Most new smartphone models manufactured in recent years utilize the Nano-SIM format due to its compact design and efficiency while providing the same functions as its larger predecessors.

The other SIM card formats, while still in use, have been largely phased out in favor of the Nano-SIM. The Standard SIM, Mini-SIM, and Micro-SIM formats were popular in earlier generations of phones, but as technology advanced and smartphone designs became more compact, the industry shifted towards the Nano-SIM. This transition reflects a trend in mobile design toward smaller and more powerful devices.