I can play 720p video without much problem. The issue there is not resolution. Assuming that you are playing H.264-encoded video, commonly used profiles of H.264 include High, Main, and Baseline. To ensure greatest compatibility at the expense of video quality, encode the video in Baseline; it would play because it requires least computational complexity compared with other profiles. On my PC, I mostly encode video in High 4:4:4, which cannot be natively decoded in Windows without installing third-party codecs, such as K-Lite Codec Pack Mega. Using High 4:4:4 makes sense for video playback in my PC to ensure maximum quality. But for mobile device, it does not offer much benefit, considering the fact that the phone only has the screen size of five inch or smaller. Handbrake is the handy tool to re-encode videos for their playback in cellphones. Some higher-end phones may be able to play computationally more complex videos but the battery life would be significantly shortened due to the greater use of processing power. Or, if you do not mind to use command-line UI, Ffmpeg is a greater tool, which provides even more customization. I have not tested 1080p videos yet. I do not care personally because I would re-encode them to 720p in Baseline Profile anyway.