Xiomi mi 4 does n’t have expandable storage.
It does not have any memory card slot .it has an only 16gb internal memory which is very less . Also the battery is nonremovable.
The phone is not suitable for those users who want to keep a collection videos, songs, HD videos. The phone also lags when playing heavy games even after having 3 gb ram. The graphic card of this phone is not of high quality therefore high graphic games does not work.