What is CDMA and GSM?
GSM (Global System for Mobiles) and CDMA (Code Division Multiple Access) are two technologies used in cell phones. They are an older form of 3G technology which helps to fill in the gap when you are in an area without 4G signal.
Older cell phones will either be a GSM phone or a CDMA phone and be locked to the carrier network, which is why it is harder with older phones to move from a GSM carrier to a CDMA carrier or vice versa. However, phones made in the last few years normally have both technologies built into them making it easier to switch carriers.
The GSM network is more well known as the technology is used worldwide, whereas CDMA networks are only used in the US. This means if you travel a lot having a phone that uses a SIM card is the best way to check if it is compatible with the GSM network.
GSM vs CDMA network coverage
| NETWORK | OVERALL | RELIABILITY | SPEED | DATA | CALL |
|---|---|---|---|---|---|
| Verizon Coverage | 95 | 96 | 94 | 96 | 94 |
| AT&T Coverage | 94 | 94 | 95 | 96 | 92 |
| T-Mobile Coverage | 86 | 88 | 82 | 89 | 82 |
Source: Rootmetrics
GSM plans on T-Mobile's network
| Carrier | Network | Data | Price |
|---|---|---|---|
| Tello 2GB plan | T-Mobile 5G/4G Coverage | 2GB | $10/mo |
| Mint Mobile 5GB plan | T-Mobile 5G/4G Coverage | 5GB | $15/mo |
| Red Pocket 10GB plan | T-Mobile 5G/4G Coverage | 10GB | $20/mo |
| Mint Mobile 15GB plan | T-Mobile 5G/4G Coverage | 15GB | $15/mo |
| Tello unlimited data plan | T-Mobile 5G/4G Coverage | Unltd | $25/mo |
GSM plans on AT&T's network
| Carrier | Network | Data | Price |
|---|---|---|---|
| Red Pocket 1GB plan | AT&T 5G/4G Coverage | 1GB | $10/mo |
| Red Pocket 10GB plan | AT&T 5G/4G Coverage | 10GB | $20/mo |
| Red Pocket unlimited data plan | AT&T 5G/4G Coverage | Unltd | $30/mo |
| Red Pocket unlimited data plan | AT&T 5G/4G Coverage | Unltd | $40/mo |
CDMA plans on Verizon's network
| Carrier | Network | Data | Price |
|---|---|---|---|
| Red Pocket 1GB plan | Verizon 5G/4G Coverage | 1GB | $10/mo |
| Twigby Mobile 5GB plan | Verizon 5G/4G Coverage | 5GB | $10/mo |
| Red Pocket 10GB plan | Verizon 5G/4G Coverage | 10GB | $20/mo |
| Visible unlimited data plan | Verizon 5G/4G Coverage | Unltd | $25/mo |
| Total Wireless unlimited data plan | Verizon 5G/4G Coverage | Unltd | $40/mo |
Is my phone GSM or CDMA?
Most modern iPhones and Samsung phones are compatible with both 3G networks but the very simplest way to be sure is that if you're currently with T-Mobile or AT&T, it's GSM compatible and if you're currently with Verizon, it will be CDMA compatible.
Phone compatibility checker
GSM carriers list on T-Mobile
Boost Mobile
Boom! Mobile
Consumer Cellular
FreeUP Mobile
Metro by T-Mobile
Mint Mobile
Red Pocket
Straight Talk
Tello
TextNow
Tracfone
Ultra Mobile
US Mobile
Good2Go Mobile
Reach Mobile
Lycamobile
Kroger Wireless
Optimum Mobile
Boost Infinite
WOW! Mobile
Gotalk Wireless
GSM carriers list on AT&T
Boost Mobile
Cricket Wireless
Freedompop
PureTalk
Red Pocket
Straight Talk
Tracfone
US Mobile
Good2Go Mobile
Boost Infinite
CDMA carriers list on Verizon
Boom! Mobile
CREDO Mobile
Lively
Page Plus Cellular
Red Pocket
Spectrum Mobile
Straight Talk
Total Wireless
Tracfone
Twigby Mobile
US Mobile
Visible
Xfinity Mobile
Affinity Cellular
Cox Mobile
MobileX
CDMA vs GSM FAQs
AT&T operates on the GSM network. AT&T unlocked phones should work with GSM carriers.
T-Mobile operates on the GSM network. T-Mobile unlocked phones should work with GSM carriers.
Verizon operates on the CDMA network. Verizon unlocked phones may only work with CDMA carriers.
Recap
Whether you choose a carrier on the CDMA or GSM network is down to preference and what your needs are. Bearing in mind that it is easier to change carriers with a GSM unlocked phone.
As technology is moving forward both CDMA and GSM are working alongside 4G, but still, play a part in giving you cellular coverage when you're in an area not covered by 4G.
When you're looking for a new plan, you don't have to just go for one of the main carriers. You can find a much cheaper deal by using one of their MVNO's (Mobile Virtual Network Operator) because they use the main carrier networks you get the same great service, but for half the price!
