Best unlimited data plans in 2021

When it comes to picking an unlimited data plan for your new phone -- whether you have an iPhone, Galaxy, another Android device or even a flip phone -- things can quickly get complicated. Unlike with home internet, where there often may be only one or two available options, most of the US can pick wireless plans from several competitors at different price points that offer similar claims of performance or coverage. 

For this roundup, I'm going to focus on the three major carriers -- Verizon, T-Mobile and AT&T -- combing through the multiple postpaid unlimited plans available to find the ones that provide the most perks and value for single lines and for families of four.

Know your area

Before we get to the plans, to get the best deal you need to make sure you have the coverage that you need. This makes it very hard for us to give a blanket recommendation of any one carrier. T-Mobile's service in New York may be excellent, but if you're in rural Iowa, Verizon is more reliable. 

Screenshot by Sarah Tew/CNET

While your mileage may vary, the good news is that these networks are growing and improving all the time, particularly as the three major players race to blanket the US with 5G. It's quite possible that a decade ago you left a network complaining about its sparse service, but now it's been beefed itself up because of that race to acquire customers.

If you know any friends or family in your area that already use the carrier you're considering, ask about their experience. You could also go to a carrier's store and see if they offer any free ways to try out the service before switching over, such as T-Mobile's Test Drive.