How to speed up your iPhone if the Spectre patch slows it down


Ghosts are a bit like spectres.
Photo: Sean MacEntee/Flickr CC

Spectre is the worst kind of security flaw. Not only do the partial fixes not even protect against attacks, but they also slow down your iPhone, or other device. But things aren’t quite as bad as they seem. You can take steps to speed up your iPhone once again, and one of the fixes not only makes the web faster, but also fixes Spectre’s biggest attack vector.


Spectre is caused by a flaw in the design of the chips that run pretty much all computers, from Mac to PC, Android to iOS. Our own Killian Bell has a great post explaining the whole situation. Software fixes can mitigate the vulnerability, but doing so can slow the CPUs in these devices enough to be noticeable.

The Spectre exploit arrives on your device in one of two ways. One is a malicious app, which can exploit the hardware flaw to its own ends. The other is via the browser, using JavaScript. The app route is not likely to be a problem with iOS, thanks to the vetting carried out for the App Store, but JavaScript is executed on your device every time you visit a site with Safari.

Turn off JavaScript

The best way to avoid Spectre is to turn off JavaScript altogether. Doing so may also speed up your browsing considerably. Most adware, and all the tracking code and other junk that modern websites infest your computer with, are delivered in the form of JavaScript. And turning it off is easy:

Disabling JavaScript is easy on iOS.
Disabling JavaScript is easy on iOS.
Photo: Cult of Mac

To disable JavaScript on your iPhone or iPad, go to Settings > Safari > Advanced, and toggle the JavaScript switch. That’s it. And this works in all web views, not just in the Safari app itself. On the Mac, you’ll find this setting inside Safari’s preferences, under the Security tab.

The downside of this is that you just broke much of the web. YouTube videos won’t play, and apps, like Gmail, that run inside the browser won’t function properly. This means that you may not be able to run with JavaScript off all the time.

Other fixes

Benchmark tests show significant slowdowns for devices running iOS 11.2.2, macOS High Sierra 10.13.2 Supplemental Update, and Safari 11.0.2 for macOS Sierra, and OS X El Capitan, which all contain mitigations for Spectre. But in practice, these slowdowns may be barely noticeable. I’ve yet to use an up-to-date iPhone that has any perceivable lag.

If you are experiencing slowdowns, then, don’t immediately blame Spectre. There could be any number of other causes.

Dead battery

As we now know, iDevices with tired old batteries may run slow. The best cure for this is a new battery, which will only cost you $29 in Apple’s new battery replacement program. With a fresh battery, iOS will no longer throttle the CPU when the battery can’t provide enough juice.

Offload storage to iCloud

If you cheaped out and bought the smallest-capacity iPhone or iPad, you may be learning your lesson. An almost-full computer will run painfully slow, and the iPhone is no exception. You can’t add storage to an iPhone, but you can reduce how much you need.

The biggest storage hog on your iPhone is likely to be photos. Instead of deleting them, consider switching on the iCloud Photo Library, which uploads your full-sized original photos to iCloud, and replaces them with smaller versions tailored to your device. Whenever you view, edit, or share a photo, the full-sized version is retrieved. This can save many gigabytes of space. Unfortunately, the default 5GB allowance that comes for free with your iCloud account isn’t really enough. The good news is that upgrades are cheap — from $1 per month for 50GB, up to $10 per month for 2GB. You can also share these plans with other family members, making it pretty economical to get way more storage.

iOS 11’s storage settings

iOS 11 has several great new tricks to free up space on iPhones. We have a great iOS 11 storage how-to, but the short version is that iOS 11 can automatically offload apps, delete old iMessage threads and attachments, and help your review space-hogging videos, among other tricks. These are not automatic, so you should check out our how-to and switch these features on.

Wait to upgrade your iPhone

The Spectre fixes are really just prophylactics. Software updates cannot fix the problem, so you’ll have to wait for new chip designs that eliminate the vulnerability. That means waiting for the next wave of Mac and iOS devices, and those won’t be around until later this year. So perhaps you should hold off upgrading to that new iPhone X until fall, when you can most likely buy a non-vulnerable iPhone instead.