How to check your iOS version and free storage on iPhone

2 min read · 4 steps · Updated 2 October 2026

The About page answers the questions support staff and second-hand buyers ask most: which iPhone is this, which iOS is on it and how much space is left.

These screens are from iOS 26 on an iPhone 17. On older versions the rows are in the same place, with a slightly different look.

Step by step

1. 

   Open Settings and tap General

   Open the grey Settings icon and tap General.

   Done

2. 

   Tap About

   About is the first row under the General heading.

   Done

3. 

   Read the iOS version and model

   iOS Version shows the software on the phone. Model Name is the name used in shops, such as iPhone 17. Tap iOS Version to see the build number as well.

   Done

4. 

   Read Capacity and Available

   Capacity is the size of the phone, for example 128 GB or 1 TB. Available is the free space right now. If Available is under about 5 GB, updates and the camera start to struggle.

   Done

Good to know

The Serial Number on this page is what Apple asks for when you check warranty or book a repair. Hold your finger on it to copy it. Do not post it publicly.

To see what is using the space, go back to General and tap iPhone Storage. The list is sorted with the largest apps first.

To check for a newer iOS version, go back to General and tap Software Update.

In short: Settings, General, About. iOS Version for the software, Available for free space.