16G is relatively small, and installing some apps will lead to insufficient memory in the mobile phone. In your mobile phone settings, you have a general-purpose one for internal use, and then click Manage Storage Space to clear how much memory some of your software takes up. Some software is not commonly used, so it is recommended to uninstall some. The photos in the mobile phone can be exported to the computer or uploaded to the Internet regularly (such as QQ space photo album, which can be seen by everyone if you want it to be seen by the outside world, or by yourself if you don't want it to be seen by the outside world). This will also free up some space. Wechat, I don't know how many groups you have added. If there are more chat records and pictures in some groups, it will take up more memory. You can also clean up the garbage on WeChat regularly. This will free up some memory. Generally speaking, 16G is not enough for current mobile phones. Just install a few commonly used software, etc. And you will feel that there is not enough memory. Therefore, you need to slim down your mobile phone regularly.