While the best unlocked phones almost certainly support GSM carriers like AT&T and T-Mobile, it’s best to look for devices that work with all the major U.S. providers, including Verizon.

One of the smallest GSM phones in the world ... It is compatible with at least some US networks, and may be available unlocked from third-party retailers, and/or from smaller service brands.

It has a removable battery, 32 gigs of storage, a microSD card slot and one of the better cameras on the market. This is an unlocked GSM phone that Microsoft sells direct and it has two SIM card slots ...