Can I use straight talk on an LG G2 AT&T unlocked phone?

[AC Question]

Gsm 4g lte

 

[B. Diddy]

Welcome to Android Central! You can check here: Phone Information

 

[Rukbat]

On a Straight Talk AT&T SIM, of course. It's still using an AT&T SIM and AT&T towers.

On a Straight Talk TMobile SIM it should work on 4G (as well as voice and text), since it has Band 4 (for 4G), but probably not work on 3G (it doesn't have the right bands).

The link B. Diddy gave you is for CDMA phones (it checks whether the carrier allows that particular phone on its network).