What is SIM (Subscriber Identity Module) card?

A SIM (Subscriber Identity Module) card is an integrated circuit card that stores the ICCID (Integrated Circuit Card Identifier) number, the IMSI (International Mobile Subscriber Identity) number, and other information about the wireless carrier.

SIM cards were introduced in different sizes:

Name        Code   Length    Width      Thickness   Introduced 
---------   ----   -------   --------   ---------   ----------
Full Size   1FF    85.6 mm   53.98 mm   0.76 mm     1991
Mini-SIM    2FF    25 mm     15 mm      0.76 mm     1996
Micro-SIM   3FF    15 mm     12 mm      0.76 mm     2003
Nano-SIM    4FF    12.3 mm   8.8 mm     0.67 mm     2012
eSIM        MFF2   -         -          -           2016

Full Size SIM Card - Full Size SIM Card was introduced in 1991 and was the largest SIM card. It was the size of a credit card (85.60 mm × 53.98 mm × 0.76 mm). Full Size SIM Cards were used in in older phones like iPhones up to the 3GS and older Android models.

Mini-SIM Card - Mini-SIM Card, also called Standard SIM Card, was introduced in 1996. Mini-SIM Cards were used in iPhones 3GS, Nokia 3310, Blackberry 9720, etc.

Micro-SIM Card - Micro-SIM Card was introduced in 2003. Micro-SIM Cards were used in Nokia 8110, Blackberry Q10, Samsung Galaxy S4, etc.

Nano-SIM Card - Nano-SIM Card was introduced in 2012. Nano-SIM Cards are used in iPhone 13, Samsung Galaxy A54, Google Pixel 6a, etc.

eSIM Card - eSIM (Embedded SIM) Card was introduced in 2016. The Samsung Gear S2 Classic 3G smartwatch was the first device to implement an eSIM in 2016. The first iPhone models to support eSIM were the iPhone XS and iPhone XR in 2018.

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⇑ SIM (Subscriber Identity Module) Card

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