"Is my phone genuine?"... Barely 3 months after the launch of the Samsung Galaxy S4 and there was already a growing number of fake versions starting to flood the market. Some of these fake phones are, outwardly, very good copies indeed and would easily pass casual inspection. Most are being sold on sites such as eBay, Craigslist and some lesser known sites, where the buyer has to rely on photos and descriptions that are supplied by the seller. Also, quite openly, these fake phones are being advertised and sold as fakes/clones on sites such as this for only US$318.22, (or less, see post #5)... Samsung Galaxy S4 Quad Core 5inch MT6589 Android 4.2 16GB Phone(1:1version) I am sure that we will be seeing more of these fake phones as time goes on and will be getting requests from posters as to the authenticity of their phone. This is not an easy task in most cases as there are so many varieties of the legitimate Galaxy S4 phones around, see 23 Galaxy S4 models - know yours?, and as I mentioned, the fakes are very good in some cases. See these videos... Real vs Fake Samsung Galaxy S4 - YouTube fake galaxy s4 - YouTube However, all is not lost as there are some apps, free, from the Play Store that can be downloaded to determine the authenticity of most of the popular S4 models... First is the "Genunie" Galaxy - Phone Info that checks the phone's details and hardware configuration and also runs performance tests and compares with other phones in the world. Claims to work on the... GT-I9500， GT-I9502, GT-I9505, GT-I9508, SCH-I959, SGH-I337, SPH-L720, SHV-E300S, SGH-M919, SHV-E300L/S/K, SCH-I545, SGH-M919, SCH-R970, SC-04E, SGH-I537, GT-SC04E, Galaxy S4 Mini, Galaxy S4 Active, models.*** Alternatively, you can download, free from the Play Store, Phone Info. This displays a whole host of information for genuine Samsung phones, including firmware details, Knox warranty and country of origin. *** For models not included above or to double check the results, I would suggest downloading, free from the Play Store, Android System Info and checking your phone in the System tab > BuildInfos. Whilst it cannot prevent anyone buying a fake S4 it can at least go some way to determining if a phone is fake or not without having to ask a lot of questions. Also, if you are purchasing a used phone, you should check out the phone's history to see if it has been lost, stolen or blacklisted for non payment of contract. This can be done by obtaining the phone's IMEI number, enter *#06# into the dial pad, and then using a service such as CheckMEND. For anyone thinking of buying a phone from the web or, indeed, any untrusted source, the watch words are... caveat emptor... Let the buyer beware!