What happen if I upgrade my iphone 6s storage?

There is no option to upgrade the storage on any model of iPhone after it is purchased.

There is an option to upgrade iCloud storage. That isn't a substitute for storage on a phone but you may be able to free up some storage on the phone if you have a lot of photos and videos. You can do that by turning on iCloud Photos and also turning on the Optimize Storage option in Photos. See the following for information on both: Set up and use iCloud Photos - Apple Support

Also see: iCloud+ plans and pricing - Apple Support

There is no upgrade to internal components.

NOTE:

Your tagline states iPhone XS.

Your iPhone 6S has reached the end-of-life support for Software Updates to the latest iOS operating system, which makes it vulnerable to online malicious cyberattacks.

You are invited to visit an Apple retail store to discuss your iPhone upgrade options.

Learn about the ⇢ iPhone Upgrade Program. ⇠📲

Good luck! 👋🏼😉

roxanevhon19 wrote:

I am planning to upgrade the storage of my iphone 6s

You cannot.

, is this a resolution for small storage?

Getting more storage can be a solution for not having enough storage – if that is your only problem, and you get enough more.

Getting any more will require purchasing a new iPhone. That iPhone's internal storage will also be fixed for its life, but you could presumably purchase a new iPhone that has more storage than the iPhone you have now.

If you get a new iPhone, I would suggest one that is compatible with iOS 18 and that is likely to have years' worth of updates ahead of it, such as an iPhone 15-series or 16-series phone.

You can’t upgrade or change the installed iPhones storage at all.

What storage space the phone has when you buy it is all it will ever have.