Just look at the recent data. Between September and early November — when Apple made the iPhone 8 available, followed by the iPhone X — Google searches for the keywords “iPhone slow” jumped about 50 percent.
The phenomenon of perceived slowdowns is so widespread that many believe tech companies intentionally cripple smartphones and computers to ensure that people buy new ones every few years. Conspiracy theorists call it planned obsolescence.
That’s a myth. While slowdowns happen, they take place for a far less nefarious reason. That reason is a software upgrade.
“There’s no incentive for operating system companies to create planned obsolescence,” said Greg Raiz, a former program manager for Microsoft who worked on Windows XP. “It’s software, and software has various degrees of production bugs and unintended things that happen.”
Here’s what happens: When tech giants like Apple, Microsoft and Google introduce new hardware, they often release upgrades for their operating systems. For example, a few days before the iPhone 8 shipped in September, Apple released iOS 11 as a free software update for iPhones, including the four-year-old iPhone 5S.
The technical process of upgrading from an old operating system to a new one — migrating your files, apps and settings along the way — is extremely complicated. So when you install a brand-new operating system on an older device, problems may occur that make everything from opening the camera to browsing the web feel sluggish.
“It’s like changing the plumbing of the house without changing anything else,” said Scott Berkun, an author and a former manager for Microsoft who oversaw engineers that worked on Windows operating systems and web browsers.
The good news is that because tech companies are not intentionally neutering your devices, there are remedies for when you think your three-year-old iPhone or your seven-year-old Windows computer has become slow or short-lived. Here’s a guide to speeding up your troubled gadgets, based on interviews with information technology professionals and operating system experts.
Tech companies make it simple to upgrade to a new operating system by pressing an “update” button, which seamlessly migrates all your apps and data over. While that’s convenient, it isn’t the best way to ensure that things will continue running smoothly.
A better practice is backing up all your data and purging everything from the device before installing the new operating system. This “clean install” works more reliably because the engineers developing operating systems were able to test this condition more easily, Mr. Raiz said.
Let’s say, for example, you have an iPhone 6 with 100 apps installed, four email accounts and 2,000 photos. It is more likely that a quality-assurance engineer tested installing a new operating system on a blank iPhone 6, rather than an iPhone 6 with the same setup as yours.
So if you want to minimize the chances of something going awry, resist the easy update path and opt for a clean install. For smartphones, I recommend backing up your data to your computer. For computers, you could back up your data to an online service or a portable drive. After the operating system installation is complete, you can then safely restore your data and apps to the device from the backup.
Remove the ‘Cruft’
Sometimes you can do some light maintenance to speed up your device. Over the long term, an operating system accumulates system files, settings, logs and other data; I.T. experts call this “cruft.” This can bog down your device.
For computers, there are some apps for cleaning up your system. Mac users can download a free app called Onyx, and Windows users can run a cleanup utility included in the system. For iPhones and Android devices, you can open the settings app and select reset settings. (Just make sure you back up first in case there are important settings you may lose.)
Be Mindful of Your Storage
Here’s something many people don’t realize: Just because your iPhone or Samsung phone has 64 gigabytes of storage doesn’t mean you should fill it all the way up. The device will generally run faster if more of its storage is available.
That’s partly because your device needs space to move data around and download software updates. But it’s also related to how the storage technology works inside smartphones and modern laptops.
Smartphones and newer laptops rely on flash storage, which stores data in the cells of semiconductor chips. When data is stored on a flash drive, it is scattered across the drive. So when you are pulling data to open an app or a document, you are retrieving it from multiple parts of the drive. If lots of space is occupied, the data gets crowded and the device may feel sluggish.
“If you fill these things up, it doesn’t get to operate as well,” said Brian Denslow, a technician for TechCollective, an information technology consulting company in San Francisco. Mr. Denslow said a good rule of thumb is to buy more storage than you think you will use. If you think you are going to use 64 gigabytes on an iPad, for example, buy the 256-gigabyte model.
I also recommend freeing up a huge amount of space by managing your photo library in the cloud. You can upload all your albums to a service like Google Photos and periodically purge all the images from the device itself. I did this recently on my iPhone 7 that was nearly full and seemed to be slowing down; purging the photos freed up about 50 gigabytes of data, and the iPhone feels as good as new.
Invest in Your Infrastructure
Your device may seem slower for reasons unrelated to the device. Mr. Denslow, the technician, said many apps relied on an internet connection, so a shoddy Wi-Fi router might be the real bottleneck.
To get a nice boost, invest in a modern Wi-Fi system. I recommend products like Google WiFi and Eero, which are so-called mesh networking systems that help you seamlessly set up multiple Wi-Fi stations to get a strong signal throughout the home. They are pricey, but upgrading your infrastructure will do more than buying a new phone.
“Instead of spending $1,000 on a phone every year, spend $500 on networking,” Mr. Denslow said. “It’s not sexy, but it provides more benefits over a long period of time.”
At the end of the day, there are many reasons your device may feel slow. New operating systems carry more powerful features that were designed to work better on new devices. In addition, developers of third-party apps typically prioritize making software for newer handsets, and sometimes they even discontinue support for old gadgets. If there are important tasks that your older device cannot do proficiently, consider an upgrade.
Mr. Raiz, the former Microsoft program manager, said he had recently encountered problems after updating his iPhone 6S to iOS 11. Some functions, like the ability to search for an app, no longer worked. Resetting the device’s settings fixed the problem, but he said he would most likely buy a new iPhone soon anyway to keep up with the latest technologies.
“There’s only so much you can do if your device is multiple release cycles behind,” he said.