The version of iOS compatible with older iPhones

If you have an older iPhone, chances are you can’t keep upgrading to newer versions of the operating system, like iOS 15 or iOS 16. Just because they can’t be upgraded anymore, doesn’t mean these devices can’t continue to be updated. Functional in many ways. And even, you may have an older version of iOS, and you can update to a more recent (albeit old) version. Or, install the security patches that Apple releases from time to time for these devices.

iOS version varies depending on the iPhone

The version of iOS compatible with older iPhones

In this first section, we are going to see which are the iPhones that have already stopped updating to iOS 16. And we will also see what are the maximum supported versions for each device. We will also see if recent updates have been released in the form of security patches, to cover security holes or specific vulnerabilities that could put our devices at risk. The iPhones that no longer update to iOS 16 are :

  • iPhone 7
  • iPhone 7Plus
  • iPhone SE 1st generation
  • iPhone 6SPlus
  • iPhone 6S
  • iPhone 6Plus
  • iPhone 6
  • iPhone 5s

Although there are older iPhone models, first of all we are going to focus on the ones on this list, since they support relatively newer versions, and have received security updates.

iPhone 5s iOS 12 is the maximum version supported by the iPhone 5S, iPhone 6, and iPhone 6 Plus. On January 23, 2023, Apple released iOS 12.5.7 for these devices. This update covers vulnerabilities and security holes in this version of the system.

iOS 15 is the maximum version supported by the iPhone 6S and 6S Plus, 7 and 7 Plus, and the 1st generation iPhone SE. On January 23, 2023, Apple released iOS 15.7.3 and it serves to fix system vulnerabilities and security holes.

The difference between 32 and 64 bit

There is a very marked difference from the iPhone 5S, and they are the processors with 64-bit architecture. Until the iPhone 5, the A processors ran on 32-bit architecture, and the latest operating system supported by the iPhone 5 and iPhone 5C is iOS 10.3.3 , released in July 2017, which fixes security issues.

iPhone 4

However, these two devices are the most restricted in terms of functions, since many applications are only available for 64-bit processors. And although there are developers who allow you to download old versions of their apps, some others do not allow you to download such old versions for performance and security reasons.

Now that we’ve seen the iPhone 5 and 5C, Apple’s last to have a 32-bit processor, let’s see what happens with the iPhone 4S, 4, 3GS, 3 and 2G, the original iPhone. Although it is more anecdotal, these are the latest versions of iOS that these devices support.

The iPhone 4S supports up to iOS 9.2. The iPhone 4 supports up to iOS 7.1.2. The iPhone 3GS supports up to iOS 6.1.6, the latest version of iOS with the old Apple look, before they made all the design change in iOS 7. The iPhone 3G supports up to iOS 4, the version released in 2010. For the iPhone 2G, its maximum version is iPhone OS 3.1.3, when iOS was not even iOS.