Is it smart to use an old smartphone?

Apple’s recent announcement that it will begin selling hardware repair kits for many iPhones and Mac computers will help extend the lives of these already durable devices. The kits will make it possible for any iPhone owner to replace a cracked screen or weak battery without leaving home.

Still, smartphones also need software upgrades. Sometimes that means installing a new version of the operating system. In September, Apple released iOS 15 software for the iPhone, to replace its year-old iOS 14 software. Google’s Android operating system, which runs on countless smartphone models, upshifted from version 11 to version 12 in October.

There’s no law saying you have to immediately install these upgrades. A new operating system can change the screen interface in confusing ways, or even introduce new software bugs. For instance, my primary phone, a two-year-old Pixel 3a XL, has run a little slower since I installed Android 12 a few weeks ago, and the same has happened to other Pixel users. That’s why many people skip operating system upgrades and stick with the tried and true.

But phone operating systems also need software patches to eliminate newly-discovered flaws that can compromise the user’s security. In September, for instance, Apple released a patch to fix a security flaw that enabled hackers to secretly plant spyware on iPhones. Such bugs regularly pop up in iOS and Android software, and Apple and Google scramble to squash them.

But as consumers buy newer models, it becomes uneconomical to keep updating a dwindling number of old phones. Inevitably, the day comes when your old phone can’t run the latest iOS or Android software. Worse yet, you’ll no longer get security patches to protect your phone from data breaches.

So how can you tell whether your phone can still receive the latest updates? That depends.

Apple makes it simple. The company’s latest operating system upgrade, iOS 15, will run on any iPhone going back to the iPhone 6s, introduced in 2015. In addition, the company distributes security updates for phones as old as the iPhone 5s, which came to market in 2013. If your iPhone is older than this, you’ve got a problem, but if not, you’re OK.

Things get a lot more complicated with Android phones. Each manufacturer has its own schedule for issuing software updates and security patches. A consumer’s best bet is to seek out the company website for further details.

But Samsung, the biggest Android supplier in the US, has adopted a relatively simple policy. The company vows to keep providing security patches for four years, for all phones made since 2019. If you purchased the company’s Galaxy S10 that year, you can count on receiving new patches until 2023. Phones purchased this year get support till 2025.

But that means millions of older Samsungs have aged out, including my Galaxy S6. Samsung halted support in 2018, just three years after the phone was made. Meanwhile, my iPhone 6s, made the same year, gets Apple’s latest security patches and newest operating system. If only it didn’t need more memory and a new battery.

Hiawatha Bray can be reached at [email protected]. Follow him on Twitter @GlobeTechLab.