Abstract: A sharp increase in web encryption and a worldwide shift away from standalone websites in favor of social media and online publishing platforms has altered the practice of state-level Internet censorship and in some cases led to broader crackdowns, the Internet Monitor project at the Berkman Klein Center for Internet & Society at Harvard University finds. This study documents the practice of Internet censorship around the world through empirical testing in 45 countries of the availability of 2,046 of the world’s most-trafficked and influential websites, plus additional country-specific websites. The study finds evidence of filtering in 26 countries across four broad content themes: political, social, topics related to conflict and security, and Internet tools (a term that includes censorship circumvention tools as well as social media platforms). The majority of countries that censor content do so across all four themes, although the depth of the filtering varies. The study confirms that 40 percent of these 2,046 websites can only be reached by an encrypted connection (denoted by the "HTTPS" prefix on a web page, a voluntary upgrade from "HTTP"). While some sites can be reached by either HTTP or HTTPS, total encrypted traffic to the 2,046 sites has more than doubled to 31 percent in 2017 from 13 percent in 2015, the study finds. Meanwhile, and partly in response to the protections afforded by encryption, activists in particular and web users in general around the world are increasingly relying on major platforms, including Facebook, Twitter, Medium, and Wikipedia.