How many times have you accidentally navigated off a webpage on your phone and wound up in unfamiliar territory because you tapped the wrong part of an ad? Probably too many. That's where ad blockers come in, and Adblock Plus, or ABP, is among the most popular among desktop users. With Apple now allowing ad blockers on iOS, it's no surprise that Adblock Plus is now a popular iPhone app, too.

Adblock Plus is available for free from the App Store. Assuming you can find it. There are several ad blocker apps with similar names and iconography. The correct one is from developer Eyeo, if that helps. Once it's installed, you'll have to set it up. Adblock Plus walks you through this process with a handy video.

Using Adblock Plus
I test iPhone ad blockers by using the Safari developer tools on both the iPhone and my trusty iMac. Just like a desktop Web inspector, this lets me view the entire structure of webpages viewed on my phone and other vital statistics. When testing, I reload the PCMag mobile page without cached information and average the data.

For this test, I used an iPhone 6 Plus. I chose this particular device because I've never used a phone the size of a boat oar, and I thought that I could grow personally from the experience. Also, it's a top device. 

The default settings for Adblock Plus allow nonintrusive ads that comply with the Acceptable Ads standards. For most of my initial testing, I left this feature enabled. I'll have more on Acceptable Ads later, but note that you can use the Settings page within the Adblock Plus app to toggle Acceptable Ads on and off.

In my testing, I found that Safari loaded 32 percent fewer resources when I went to PCMag.com with Adblock Plus installed. Resources include fonts, images, and other elements that make websites work. That includes resources used by ads. Adblock also limits the cookies loaded, and I saw that Adblock loaded 30 percent fewer cookies. Fewer resources means sites take up less space, and I observed that Adblock Plus reduced the total website size by 17.2 percent. This was reflected in a 21.8 percent decrease in page load time.

Sites with more elements that can be blocked by Adblock Plus have even more remarkable results. CNN.com, for example, loads 201 resources, equating about 6.3MB of stuff, in 10.5 seconds. With Adblock Plus in its default configuration, it drops to 136 resources, equaling 4.8MB, in 5.8 seconds.

Sometimes when you use ad blockers, sites don't load correctly. This is usually because the site is just not set up to work properly with elements being blocked. Crystal lets you alert the developer to the issue, but Adblock Plus does not include this feature. That's too bad. Other blockers, including 1Blocker, let you manually add a site to a whitelist and allow it to load ads. Adblock Plus has no such feature.

It's difficult to compare the ad-blocking abilities of one app with another. Websites frequently load different content for different users at different times. However, I did note Crystal blocked more resources, further reduced the size of websites, and loaded pages about a second faster than Adblock. 1Blocker, with all of its numerous blockers enabled, beat both. Even with Adblock Plus configured to reject all ads, it didn't perform as well as the competition.

Many ad blockers claim to improve battery life and protect your privacy by preventing data-hungry trackers from monitoring you online. These are both important topics, but ones that are currently outside the scope of my reviews.

Not All Ads
Some people don't like the idea of the Acceptable Ads policy, which is a series of requirements ads must meet in order to be exempted from ad blocking. Adblock Plus is a longtime proponent of the system, and newcomer Crystal has said it will include Acceptable Ads as an option in a future release. Critics complain that because the organization accepts money from some companies that it is effectively pay-for-play. Others simply just want to block all ads; no exceptions.

Whatever your feelings, toggling Acceptable Ads on or off is very simple in Adblock Plus. But what surprises me is how little impact it seems to have. Remember those CNN.com stats from two paragraphs ago? When the exemption for Acceptable Ads is deactivated (theoretically blocking all ads) Adblock Plus only blocked four additional resources, which had no effect on the size of the site or the loading speed.

Blocking With the Best
Since Apple made the announcement that it would allow content blockers, a debate has flared up around such products. One side says media consumers are obliged to view ads on sites that make money from online advertising. The other side says that people have the right to block unwanted content and control their privacy online. I'll only add that I am confident companies can adapt to a marketplace that demands higher quality. To say otherwise invalidates everything tech companies claim about their intelligence and ability to innovate.

Adblock Plus lives up to its claim of blocking content on the mobile Web, improving site loading time, and reducing the amount of data required to surf. If you opt to exempt Acceptable Ads, you don't get the best performance but do enable the online ad economy. It's up to you. If you simply want smaller websites and shorter load times, however, you'd be better off looking to our Editors' Choice for iPhone ad blockers, 1Blocker.