But the truth is more complicated.
In reality, if you use too much data in a month — even if you pay for one of these plans — your carrier might drastically slow your connection down. If you go over your plan's cap, you won't have to pay overages, but your data might be so slow that you won't be able to do very much online other than load mobile websites and check e-mail.
So, while your plan might be technically unlimited in the sense you can use as much data as you want, you're still effectively locked into a data cap because of the slower speeds your carrier might impose after you go over.
Recently, the major carriers have added tiers to their unlimited data plans with larger caps of high-speed data. It's confusing.
I took a look through the so-called unlimited plans offered by the big four U.S. carriers to find out what you actually get when you pay for "unlimited data."
They all have some perks that attempt to make the plans more enticing, like free TV, international data or a subscription to Netflix, depending on the carrier. But I want to show you, specifically, what the term "unlimited data" actually gets you in each case. If you're interested in the other perks, click the link to each plan below.
Here's what I learned.