A USB modem usually looks like a bulky USB flash drive. Once you insert it into the USB port of your laptop, you'll be able to use your mobile broadband plan to access the Internet. A USB modem connects only one device at a time, while a mobile hotspot (discussed in the next section) can connect several devices at once. USB modems can deliver faster downloads and uploads, though, and -- unlike mobile hotspots -- there's no battery to conk out on you.
The Verizon Pantech 4G LTE USB Modem UML290 (*Est. $50 with two-year contract) impresses experts more than any other current USB modem. Two of our most reliable review sources -- PCMag.com and Mobile-Broadband-Reviews.com -- both pick the Pantech as the best USB modem available on Verizon's top-rated 4G network.
It's "ridiculously fast," concludes Marc Aarons at Mobile-Broadband-Reviews.com, after the Pantech chalks up download speeds of 20.29 Mbps and uploads of 8.43 Mbps in his Atlanta test. And its speeds are consistent, too, says PCMag.com. Head-to-head against Verizon's other USB modems -- the Verizon LG 4G USB Modem VL600 (*Est. $100 with two-year contract) and Verizon Wireless 4G LTE USB Modem 551L (*Est. $100 with two-year contract) -- the Pantech proves slightly faster most of the time. It averages 16 Mbps download and 5.75 Mbps upload in PCMag's New York City 4G tests, dropping to 1.5 Mbps download in 3G mode.
The Pantech again beats the VL600 in Laptop Magazine's New York City tests, with speeds similar to PCMag's. But the Pantech narrowly misses an Editors' Choice award when it starts dropping the connection. "Early on in our testing, the UML290 had trouble holding onto a connection in a moving vehicle," Laptop's Mark Spoonauer says. "During our hour-plus daily commute to New York City from central New Jersey, we experienced an average of four to five disconnections in both directions, especially as the modem tried to latch onto a 4G signal (or fell out of 4G coverage) … However, during other trips the UML290 stayed connected for over an hour. We found the modem to be more reliable when we made sure the rotating door to the USB plug was closed." Customers who post reviews for the Pantech on Verizon Wireless's website are mixed: Many complain about dropped connections, while others report no problems. PCMag's testers say they'd "seen some complaints about both of Verizon's 4G modems having trouble in areas at the edge of 4G coverage," but "we didn't see any dropped connections in our tests."
The Pantech has a unique design: Its USB connector is not only protected by a swiveling cover (as Laptop Magazine notes above), but it also swivels itself. That way, you can rotate the modem's 3.5-inch body so it's not sticking awkwardly out of the side of your laptop. Experts say that reduces the chance that someone will hit it and twist the USB connector, which would probably break both the modem and your laptop. The Pantech also has two external antenna ports -- one for 3G and one for 4G -- if you want to boost your signal.
No other USB modems can compete with Verizon's in speed tests -- largely because they're not running on Verizon's super-fast 4G network. But if you're on a different network, experts do have some clear preferences.
The Sprint 3G/4G USB U600 (*Est. Free with two-year contract) "is the best way to connect to Sprint's 3G and 4G networks right now," editors at PCMag.com say. Mobile-Broadband-Reviews.com editors agree, recommending it over all other Sprint USB modems -- partly because, unlike them, the U600 works with both 3G and 4G signals, so you're covered if you roam out of Sprint's 4G area. The U600 delivers an average download speed of 4.6 Mbps and just under 1 Mbps upload when PCMag.com tests it in 12 locations throughout New York City, but after switching to 3G, downloads drop to 0.45 Mbps in the lower concourse of Grand Central Station. Tester Alex Colon points out that you'll certainly get faster speeds from the top-rated Verizon Pantech 4G LTE USB Modem UML290, but Sprint does offer unlimited 4G access, while Verizon's priciest plan tops out at 10 GB per month (*Est. $80).
The T-Mobile Rocket 3.0 (*Est. $100 with two-year contract) is T-Mobile's first USB modem that can support its new, enhanced 4G network that promises "theoretical peak" download speeds of up to 42 Mbps in certain cities. In reality, CNET says the Rocket 3.0 averages 6.7 Mbps downloads in several locations in and around San Francisco (which is supposed to have the new, faster service). In New York City (which doesn't have the faster service), the Rocket 3.0 averages 4.1 Mbps downloads in PCMag's tests. That's just a little faster than the older T-Mobile Jet 2.0 (*Est. $30 with two-year contract) -- enough to make the Rocket 3.0 "your best choice right now" on the T-Mobile network, PCMag says.
AT&T's USB modems don't get many recommendations -- largely because critics find AT&T's underlying mobile broadband network slow. If AT&T is the best bet in your area, though, Mobile-Broadband-Reviews.com recommends opting for the AT&T USBConnect Shockwave 4G (*Est. Free with two-year contract). It can work with AT&T's current 3G and 4G networks, and when AT&T rolls out the faster LTE 4G network it's planning, the Shockwave will work with that, too.