How to Check CDMA or GSM

This minHour teaches you how to determine whether your phone uses a CDMA network or a GSM network. Knowing this information is important if you want to remove a carrier lock from your phone, or if you want to use a specific carrier's SIM card in your unlocked phone.


Take into account your location.

Unless you’re using a phone purchased in either the United States or Russia, your phone most likely uses GSM.

  • Even with the US using CDMA with two of its major cellular networks, only around 18 percent of cellular networks in the world use CDMA.

Understand that most smartphones use LTE.

CDMA and GSM are 3G networks, but both CDMA- and GSM-networked phones are able to use 4G (LTE) as long as the smartphone itself supports a 4G-enabled SIM card. This means that choosing between CDMA and GSM may not be necessary if you’re not attempting to switch to a different network.

  • This means that your phone having a SIM card no longer helps determine whether you’re using CDMA or GSM.

Consider your current carrier.

By default, Sprint, US Cellular, and Verizon use CDMA for their phones, while AT&T, Virgin Mobile, and T-Mobile use GSM. If you bought the phone from a carrier, simply knowing the carrier’s name will be enough to tell you what the network type is.

  • Verizon phones come equipped with CDMA, but they also support GSM.
  • If you bought an “unlocked” phone, that means the phone itself can be used on any carrier’s network. In which case, knowing current carrier’s network won’t tell you if your phone uses GSM or CDMA.

Check your phone’s “About” settings.

If you see a or an category, your phone requires CDMA; if you see an category, your phone is GSM. If you see both (e.g., Verizon phones), your phone supports both CDMA and GSM, and may use either network. Use the following steps to check your phone’s “About” settings:

  • iPhone:Open the Settings app.Tap General.Tap About.Scroll down to look for the MEID (or ESN) or IMEI number.
  • Open the Settings app.
  • Tap General.
  • Tap About.
  • Scroll down to look for the MEID (or ESN) or IMEI number.
  • Android:Open the Settings app.Scroll down and tap System (Android Oreo only).Tap About phone.Tap Status,Look for an MEID (or ESN) or IMEI number.
  • Open the Settings app.
  • Scroll down and tap System (Android Oreo only).
  • Tap About phone.
  • Tap Status,
  • Look for an MEID (or ESN) or IMEI number.

Look up your phone’s model number.

If you still can’t determine whether or not your phone is CDMA or GSM, try looking up the phone’s model number. You can find this in the phone’s manual, or you can check your phone’s settings. An online search will display the type of network associated with the phone model.

  • iPhones have the model number listed on the back of the phone’s housing, though the number can be difficult to see if you have a black or space-grey version.

Check your phone’s specifications.

The documentation that came with your phone should have a list of specifications that say whether or not your phone uses GSM or CDMA. You can also check the specifications for your phone manufacturer’s website.

  • If you no longer have your phone’s model, try visiting the phone manufacturer’s site, and looking up the type of phone you have (e.g., iPhone 7, jet black, 128 gigabytes). You can narrow it down from there.

Call your current carrier.

If you have a current carrier, you can call them to ask whether your phone is CDMA or GSM. They will most likely need your phone’s IMEI or MEID number, as well as your name and other account information.

  • Again, if your phone is unlocked and has never used a specific carrier, you’ll have to look up the phone’s model number. Calling a carrier won’t work.


  • GSM phones are most commonly used throughout Europe and Asia, and are usually preferred while traveling due to their modularity.
  • When you take your phone into a carrier’s shop, you may be able to determine whether it supports both networks. Some phones, such as certain models of Verizon phones, support both CDMA and GSM networks via multiple SIM card slots.


  • If you can’t find your phone’s model number anywhere, you may need to take the phone into a manufacturer shop (e.g., an iPhone would go to an Apple store and a Samsung Galaxy would go to a Samsung dealer) to have a professional determine your phone’s model and network type. This is usually free.

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