Here's how the 'unlimited' plans from Verizon, AT&T, Sprint, and T-Mobile compare (VZ, TMUS, S, T)

Verizon Lowell McAdam

Everything old is new again, and unlimited data plans are back in vogue.

After months of tweaks and updates, the unlimited plans from all four of the major mobile carriers in the US seem to be in a relatively stable place.

But, per usual, all of those plans still come with a significant slate of caveats.

So to help you sort through the fine print, here's a quick rundown of how this revived set of unlimited plans match up.

The big caveat: No "unlimited" plan is really unlimited.

Wireless carriers use the word "unlimited" in a misleading way.

No "unlimited" plan here allows you to use an endless amount of LTE data across the board with no penalties. Instead, each carrier warns that it may slow your speeds if you use a certain amount of data in a month and live in an area of congestion.

Each plan also limits what you can do with that data when it comes to things like mobile hotspots, international usage, and the like.

And the situation only gets worse when you look at the restrictions imposed on unlimited plans from mobile virtual network operators (MVNOs) like Boost Mobile and Cricket Wireless, or on the prepaid "unlimited" plans from the major carriers themselves.

Also, none of the carriers' advertised rates includes device subsidies. If you buy a phone from a carrier and pay for it in monthly installments, that fee will be added to the cost of your plans.

Still, the "unlimited" plans have value. At least with the major carrier plans, you do truly get unlimited talk and text, and the amount of data you can use without risk is fairly generous. And being slowed in areas of congestion is not the same as being outright throttled; even after passing a carrier's warning point, you can still get LTE speeds.

The other caveat: Not all networks are created equal.

A good "unlimited" plan isn't as worthwhile if it comes with shoddy internet. Sadly, a big chunk of the country still suffers from mediocre mobile coverage.

It's hard to give exact metrics on how the carriers' current networks compare, but a recent PCMag report found Verizon to have to best mix of speed, coverage and reliability, with T-Mobile and AT&T close behind. A recent RootMetrics study, meanwhile, found a bigger gap between AT&T and T-Mobile, but also said Verizon is tops in terms of overall quality.

In general, Verizon is consistently near the top, T-Mobile is said to be vastly improved from years past, AT&T is either in second or third, and Sprint typically brings up the rear. Much of the time, though, which is best for you depends on where you live.

If you opt for a prepaid carrier, you usually have to deal with slower speeds. Cricket Wireless has an unlimited plan for $65 a month, for example, but its parent, AT&T, caps Cricket download speeds at a lower-than-average 8 Mbps.

Sprint, meanwhile, caps all video on Virgin Mobile's and Boost Mobile's unlimited plans at a less-than-HD resolution. Virgin did recently introduce an enticing deal that offers a year's worth of data for $1, but you need to buy a new iPhone outright to be eligible for it.

And the prepaid "unlimited" plans from carriers like Verizon and T-Mobile block things like HD video streaming and the ability to use your phone as a mobile hotspot. As a result, we've omitted all of these prepaid plans from this comparison.

Verizon

How much does it cost?

$80 a month for one line. $140 a month for two lines. $160 a month for three lines. $180 a month for four lines. The cost per line then gradually decreases until you hit $300 a month for 10 lines.

For plans with multiple lines, you can share that data across smartphones and tablets.

None of this includes taxes and regulatory fees. Those vary by region, so your bill will be a bit higher than what's advertised.

You also need to set your service to automatically pay your bill each month. Otherwise, a single line costs $5 more a month, and users with up to 10 lines will pay $10 more a month.

How much LTE data do you actually get?

Verizon says your line may be temporarily slowed in areas of congestion if you use more than 22 GB of LTE data in a month.

Can you stream HD video?

Yes. And Verizon says it doesn't "manipulate the data" it sends over video in any way.

How about LTE mobile-hotspot data?

Yes. You get 10 GB of LTE mobile-hotspot data per line each month. Verizon says mobile-hotspot speeds will be reduced to slower 3G speeds once you exceed that amount.

Any other details worth knowing?

Verizon still offers less-expensive, non-unlimited plans on its website. Those range from $35 a month for 2 GB of LTE data to $70 a month for 8 GB of LTE data.

Verizon also offers unlimited calling and texting from the US to Mexico and Canada. It also allows data usage in those countries, but caps you at slow 2G speeds if you use more than 500 MB of data in a given day, which isn't a lot.

See the rest of the story at Business Insider