I'm using iPhone 5s 16gb right now. And the iOS is iOS 9. I should upgrade the iOS. Do you think iOS 10.3.3 is safe for my iPhone 5s 16gb? Thank you.

iOS 10.3.3 is save for your iphone 5s. I would recomend you to update to ios 10 unfortunately it is no longer possible. You can only update to iOS 11 but do not do that it will slow down your device. Hope I helped.

I'll be the odd-man out and recommend that you stay where you are on iOS 9.x.x. If you have no need to update (apps requiring a higher iOS) and the device is running fine as it is, just stay where you are. There's nothing *requiring* you to update if you don't have the need to.

As others have mentioned, if you choose to update, you will be updated to the most recent iOS that your device qualifies for. You cannot pick & choose the update that you want to run.

Yes, I myself am (still) staying at iOS 9.3.5 on my iPhone 5S for the time being...a lot longer than I expected but my device is running great as it is. The new "features" of iOS 11.x.x don't interest me in the least bit.

As always, you can only update to the latest available version.

All updates are safe.

It doesn't matter. It's no longer possible to install iOS 10.3.3 on a device capable of running 11.1.1.

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