Hi I have couple of questions regarding space on my iphone 5s, IOS 10.2 Q1) available space shown in my iphone (2,93 GB) is different than what shown in Itunes when I connect it to mac (3,5 GB). Any explanantion? what to do? Q2) In my Storage & iCloud Usage > Manage Storage, I have around 1,16 GB used space by messages. However, I have deleted all messages from all my apple products. How do I delete that? I have almost try everything advised on internet. This might be related to question 1. Q3) when I connect my iphone to mac and open Itunes, in movie section from left side, I have a video that I do not know how to delete it. how to delete? Q4) every now and then, 3 deleted videos and a picture, show up in my photos on iphone. No matter how many times I have deleted them, they keep showing up like once every 3 days.
There are a few ways you can clear up space on iOS. First of all, there are apps on the iTunes Store that clear up junk on your disk. I used one of these and it opened up 4GB without deleting anything that I noticed. You can also delete browsing data by going into Settings > Safari > Advanced > Website Data. Scroll down to the bottom and click 'Remove all Website Data'. You can also just delete data. There are some others, but there are just a few.
I know this doesn't answer all of your questions but hopefully, it helps some.