How to Determine if iPhone is GSM or CDMA

Most of us geekier folks instantly know if our iPhones are CDMA or GSM models, but not everyone pays as much attention to the largely insignificant technical details of their phones. Not to worry, it’s extremely easy to find out if an iPhone is GSM or CDMA, all you need to do is look at the model number of the device.

To find out if the phone is CDMA or GSM, flip the iPhone over and look at the back. Locate the string number alongside “Model” and compare it against this list:

iPhone GSM Model Numbers

• iPhone 5: A1429 (* World GSM & CDMA)
• iPhone 5: A1428
• iPhone 4S: A1387 (* dual band CDMA & GSM world phone)
• iPhone 4S: A1531 (GSM China)
• iPhone 4: A1332
• iPhone 3GS: A1325 (GSM China)
• iPhone 3GS: A1303
• iPhone 3G: A1324 (GSM China)
• iPhone 3G: A1241
• iPhone 1: A1203

iPhone CDMA Model Numbers

• iPhone 5: A1429 (* World GSM & CDMA)
• iPhone 4S: A1387 (* dual band CDMA & GSM world phone)
• iPhone 4: A1349

Knowing the model numbers is guaranteed and is pretty quick, and it’s also the best way to determine what model an iPhone is that won’t turn on. For customers in the USA, another easy way to tell if it’s GSM or CDMA is just to find out what cell carrier the iPhone uses. AT&T is always GSM, T-Mobile is always GSM, while Verizon and Sprint are always CDMA. You can also generally assume that if it uses a SIM card to get online, it’s a GSM iPhone, though some iPhone models like the iPhone 4S have both CDMA and GSM capabilities. The cell carrier isn’t always a reliable method though, because sometimes an iPhone won’t turn on, is out of battery or just plain dead, or it could even be a dualband world phone like the 4S.

What if the iPhone Model Number is Rubbed Off?
You can also get the same Model number information by connecting any iPhone to a computer with iTunes. If that isn’t an option, open Settings, tap General then “About”, and look under “Network” or “Carrier” instead.

Why Does it Matter?
For the vast majority of iPhone users, it doesn’t, they’ll never need to know or care about their device being GSM or CDMA. This is really mostly helpful to those who use IPSW (IPSW is iOS firmware, basically the iPhone system software) to either update a device manually, for jailbreaking purposes, or for restoring a device in the event of a significant software failure. In that case, knowing which model a device is important when downloading IPSW files for iPhones.

Thanks for the tip jlfafi!