SIM Form Factors: 1FF vs 2FF vs 3FF vs 4FF

SIM (Subscriber Identity Module) cards come in different form factors, which refer to their physical size and shape. The four main form factors are 1FF (First Form Factor), 2FF (Second Form Factor), 3FF (Third Form Factor), and 4FF (Fourth Form Factor).

Each form factor is designed to fit into different types of devices and has evolved over time to accommodate the changing requirements of smaller and more compact devices. Here’s an overview of each SIM form factor:

1FF (First Form Factor)

Also known as the “Full-size” SIM card.

• Dimensions: 85.60 mm × 53.98 mm × 0.76 mm
• This was the original and largest SIM card size.
• Used in early mobile phones but is now obsolete due to its large size.

2FF (Second Form Factor)

Also known as the “Mini-SIM” or “Standard SIM” card.

• Dimensions: 25 mm × 15 mm × 0.76 mm
• Became the standard SIM card size for a long time.
• Used in a wide range of mobile phones until more compact sizes were needed.

3FF (Third Form Factor)

Also known as the “Micro-SIM” card.

• Dimensions: 15 mm × 12 mm × 0.76 mm
• Introduced to save space in smaller devices.
• Commonly used in devices like the iPhone 4 and iPad.

4FF (Fourth Form Factor)

Also known as the “Nano-SIM” card.

• Dimensions: 12.3 mm × 8.8 mm × 0.67 mm
• Currently the most widely used SIM card size.
• Commonly found in modern smartphones, tablets, and other compact devices.

Difference between SIM card sizes

Conclusion

The evolution from larger to smaller SIM form factors has been driven by the demand for smaller and more portable devices. As technology has advanced, manufacturers have sought ways to reduce the size of SIM cards while maintaining their functionality.

It’s worth noting that while these are the standard form factors, there are also adapters available that allow the use of smaller SIM cards in devices designed for larger ones. Additionally, embedded SIM (eSIM) technology is gaining popularity, eliminating the need for a physical card in some devices.