Is it still safe to be using iOS 17.3.1 and macOS Ventura in 2025 and 2026

Any update for an iPhone 13 Pro will get you iOS 18.5. Which is current.

Which macOS versions are supported depends on which iMac model and year.

Yes, there are known issues with older versions. Whether those will affect you, or what other risks you might have, nobody here knows.

Security issues are different from other sorts of bugs though, as even obscure security issues can and variously do become endemic over time, where more mundane sorts of bugs usually involve only specific configurations, and those conditions don’t become more commonly triggered.

If you want to risk this (and it’ll probably be a minor risk to start, and that risk will probably increase as the versions age out), have backups. Preferably with some backups kept offsite.

You’ll have similar issues arising with network connections over time, as connection security requirements are incrementally increased by websites and services being accessed. macOS 10.13 and 10.14 are getting dicy for instance, but how fast newer versions will fall off acceptable connection security is not known and not predictable.

For 2025, yes, and I concur with dialabrain that you should update both to the latest versions.

However, this fall Apple will introduce a new version of macOS (v26 or Tahoe), which is currently in beta. As such, Apple typically only supports security updates for the latest three versions of macOS. With Ventura being the third currently, it will drop off that support when Tahoe is released.

This, potentially, can also hold true for both iOS and iPadOS.

Mikey8834 wrote:

I watched the macOS Tahoe review videos and i don't like the way it looks epically that transparent ui thing. And my computer struggled running sonoma so i downgraded it to Ventura which it is running greatly.

You've told us nothing about your Mac, but you seem determined not to continue to update the macOS, which is of course your prerogative.

As others have posted earlier, the best guidance is to keep the macOS updated. To do less is to prematurely limit the useful lifespan of your Mac. Many users put off upgrading the OS for many reasons, only to realize later that they are many generations behind functional and security changes that happen in the OS and apps.

For example, if you stick with Ventura, then by the end of this year you will be three generations behind the current OS with Ventura support flagging. The productive usefulness of a Mac running Ventura vs one running Tahoe may be at least three years less at the end of the road.

What model and year iMac do you have. It must be at least a 2019 to be able to run Sonoma. I'm running Sonoma and it's blazingly fast. But then I'm on a Mac Mini M4 which is eons beyond the intel Macs.

I had a 2017 Intel iMac that ran Ventura 13.7.5, and it was extremely stable. You should at least update to the last and latest Ventura.

Yes. Although you should update to the latest versions. iOS 17.7.2 and Ventura 13.7.6.