Apple introduced a host of new features with iOS 9. One of the most controversial is the APIs that allow third-party developers to create Content Blocking Extensions. These extensions can be used in Safari on iOS devices to block specific sites from loading content.
Although most of the press coverage has focussed on Content Blockers being used to block ads, they can also block any other content such as comments, or even entire sites.
Content Blockers only work on recent iDevices running iOS 9. Any iPhone newer than an iPhone 5s, iPad newer than the iPad Air or Mini 2, and iPod Touch newer than the sixth generation can run them.
Content Blockers Explained
Content Blockers, or rather Content Blocking Extensions, are apps that block Safarion iOS from loading blacklisted content.
Before considering how they work, it’s important to understand the state of modern webpages.
As computers have become more powerful—and broadband more prevalent—web content has become a lot more complex. Fifteen years ago, when you loaded a site, very few resources were called that weren’t from the site’s server. It was just too demanding on computers and bandwidth to make multiple calls to different servers. That’s not the case now.
Most websites call multiple resources from other servers. These can be innocuous things like Google Analytics which keeps track of how many views each page is getting or JavaScript libraries that power the interactive effects on the site.
On the other hand, they can also be malicious ad networks that install cookies—or even malware—that track your every move.
When Safari loads a webpage, content is likely called from multiple servers. If any is called from blocked sites, it isn’t loaded alongside everything else.
Depending on what Content Blocker you are using, the JavaScript necessary to power a lightbox may get loaded while the scripts that install tracking cookies or display ads aren’t.
The Pros and Cons of Content Blockers
The bloat that’s occurred with webpages isn’t that noticeable on most computers; they’re normally fast enough and connected to a decent Internet connection so no matter how many resources from different servers are being called, they can just power through.
The problem is when you’re using a relatively underpowered smartphone in an area with patchy 3G signal. Many of the additional resources websites load are quite large. Some webpages can have more than 15 MB of additional content. Loading this content can seriously slow down a smartphone, uses lots of mobile data and wastes battery life.
When Apple announced that they were allowing Content Blockers, this was the point they emphasised. With a Content Blocker installed, webpages can load significantly quicker, use less mobile data and preserve battery life. Leading Content Blockers, Crystal and Purify both claim that they can load websites four times faster using around half as much data compared to when they’re not enabled. Their claims seem to hold up when put to the test.
Another, more controversial, benefit is that by blocking ads and tracking cookies, you protect your privacy. For the past few years ad networks have been doing everything they can to keep tabs on what you do online so they can build a profile to serve more relevant ads.
People, however, are now a lot more privacy conscious online so there is a lot of backlash to this.
The problem though, is that many websites make money by serving ads. They are able to offer their content for free because of them.
If users block ads and then access the site, they are still costing them money—servers and writers aren’t free—without giving anything in return. This creates a bit of a moral quandary where Content Blockers are concerned.
Available Content Blockers
Although iOS 9 has only been out for a few weeks, as I write this, there are already a good few Content Blockers available in the App Store. Here are some of the most popular or interesting ones you can get.
Crystal
Crystal is currently the top ad blocker in the app store. It blocks ads, user tracking and “general website annoyances”. Crystal is extremely simple to use, it’s either on or it’s off. There’s currently no way to fine tune what’s blocked or whitelist sites.
Purify
Purify is the other top ad blocker in the app store. Purify offers a lot more control over exactly what is blocked than Crystal. For example, you can whitelist websites or choose to block all images from loading.
Discontent
Discontent doesn’t just block ads and tracking scripts. It blocks everything. It’s tagline is, “Stop distracting yourself with marginally informative blog posts and start living.”
While it at first might seem like a joke, Discontent can actually serve a serious purpose. If you constantly procrastinate using an iPhone, it can make it that little bit harder making Safari useless.
Shut Up
Internet comments are the worst. You can watch a wonderful YouTube video and then scroll down and enter a world of hate and typos. Shut Up is a Content Blocker that solves that problem by hiding comments everywhere. You can even whitelist sites, like Tuts+, that has great commenters.
Installing and Using a Content Blocker
Content Blockers fade into the background once you’re using them. If they’re doing their job, you shouldn’t notice them. They’re not something you have to actively use each time.
The process for installing all Content Blockers is the same.
First, navigate to the App Store and download the Content Blocker you want to install. When it’s downloaded, head to the Settings app. Tap on the Safari button and then on Content Blockers.
Turn on any Content Blockers you want active. With that done, Safari will start using your chosen Content Blockers whenever you load a website.
Content Blockers with additional features, like Purify, can be configured from their respective app. You can also control most Content Blockers from Safari’sExtensions menu.
To reload a site without Content Blockers, hold down on the Refresh icon in Safari. You will be presented with the option to Reload Without Content Blockers.
Conclusion
Content Blockers are new in iOS 9. They selectively block Safari from loading resources from specific sites. While ad blockers are the most popular, there are other content blockers available.
Blocking unnecessary content can significantly speed up your browsing while using less mobile data. Unfortunately, unnecessary content normally includes ads which introduces a moral dimension to the decision.
This tutorial has featured a small handful of the Content Blockers available. If you use one that I haven’t mentioned, please let me know what it is and why you use it in the comments.
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