With only so much real estate on a smartphone, consumers are more often cutting ads out of their small screens to get more space to view what they really want to see.

About 419 million consumers, or 22%, of the 1.9 billion global smartphone users have installed an ad blocker, nearly double the percentage of a year ago, according to the “2016 Mobile Adblocking Report” from PageFair Ltd., a company that works with web publishers to fight ad-blocking software. PageFair collaborated with mobile app intelligence firm Priori Data on the report.

Browsers that block ads are the most popular type of mobile ad blocker, according to the study. Here’s a breakdown of the different ways consumers can block ads on their smartphones:

Ad blocking browsers

Consumers can download a browser that automatically bocks ads on webpages, such as UC Browser, Adblock Plus and Brave Software Inc. Consumers can also configure several types of browsers to block ads.

Apps

Consumers can download one of more than 200 apps, such as Crystal Adblock and Adblock Plus, that block ads within a mobile browser. Other apps, such as Weblock and Infy Block, can block ads in a mobile browser and block ads in other mobile apps.

Phone network provider

Mobile phone network providers Digicelgroup.com, Three and Shine block ads in a smartphone’s internet service provider network before it reaches a consumer’s smartphone.

Mobile ads can cause web pages to load slowly and eat up a consumer’s data, which has spurred ad blocking popularity.  As of March 2013, 2.3 million U.S.  consumers were using a mobile ad-blocking browser. More consumers are using ad blockers in China (159 million ad blocking browser consumers), India (122 million) –both of which have much larger population than the U.S.—and in emerging markets.

“Mobile ad blocking is a serious threat to the future of media and journalism in emerging markets, where people are coming online for the first time via relatively expensive or slow mobile connections,” PageFair writes in the report. Ad blocking in these markets is more attractive to speed up the mobile site load time. This could hinder media sites that rely on advertising impressions and brands that advertise on these sites.

Some ad blocking apps have a default setting preventing the display of content with tracking codes or content from vendors that share data with advertising companies. That’s because it deems such content as an ad, even though it may not be, or it deems the content as an invasion of privacy since it is tracking consumer activity.

Last September, mobile ad blocking buzz emerged after Apple Inc.’s iOS 9 operating system update allowed users with newer iPhones to install ad blocking apps for the first time on Safari, Apple’s default mobile web browser. Despite the hype, those ad-blocking apps accumulated only 4.5 million downloads, according to the PageFair study. 1.9 million of those downloads are from U.S. consumers, and PageFair estimates that only 2% of U.S. iOS 9 consumers use a content-blocking app.