Bring me new horizons: Apple will add Safari web extensions to iPhones and iPads

Something pretty amazing just happened. Apple defied the odds by bringing Safari web extensions to mobile devices. They announced it on June 7 at WWDC21*. Starting with iOS 15 and iPadOS 15, coming this fall, iPhones and iPads will have access to web extensions. Previously, they were only available in Safari on macOS.

*⠀Apple Worldwide Developers Conference

What does it mean for developers?

Now it will be possible to create universal extensions that will run on all Apple devices — Macs, iPhones, and iPads! Read on to learn more about it and to know why this is so important.

A year ago, last June, Apple added support for the WebExtension API to Safari on macOS in a similar way. To recap, "an application programming interface (API) is an interface that defines interactions between multiple software applications or mixed hardware-software intermediaries".

Previously we published a blog post about this, painting an overall gloomy picture of the situation. Back then, the arrival of the WebExtension API didn't bring any value for content blockers on macOS, so we found that news even discouraging. But this iOS situation is dramatically different: on this platform, there were no extensions at all, and now they appeared, opening up a bunch of possibilities for us. Of course, such a transformation couldn't be more welcome!

What does it mean for you?

In light of this news, our recent articles... well, they don't become irrelevant, but their meaning does change. Do you remember when we wrote about the problems with YouTube and Safari Content Blocking? On the one hand, iOS user problems listed there will not magically disappear and everything described in this artile remains in force: the declarative approach still has a lot of loose ends. In all fairness, we can see from the Safari bug tracker that Apple don't plan to leave things as they are — for instance, they've already increased the rule limit from 50,000 to 150,000. But on the other hand, support for Safari browser extensions opens up new opportunities, because the declarative approach to ad blocking is enhanced by the ability to use a content script executed directly on the page.

With this embedded script, we can implement the logic required for more advanced blocking methods. Users of AdGuard for Safari on macOS are already familiar with them, as these methods are presented in an extension called "AdGuard Advanced Blocking". So if you have an iPhone or iPad and still encounter websites that bypass ad blockers or YouTube ads while watching it in a browser — don't you worry, we'll deal with everything in iOS 15! :)

Viewed from a broader persprective, iPhone and iPad users will have an opportunity to install numerous extensions previously available only in Safari on macOS — not only AdGuard or content blockers, but any extensions you like. The arrival of web extensions on mobile devices will expand the functionality of the Safari browser and offer users a range of new opportunities.

In a nutshell, this is a revolutionary change, on an equal basis with the introduction of Safari Content Blocking in 2015, and we strongly believe that it will have a very positive impact on the quality of ad blocking in AdGuard for iOS.