This is an accessible and comprehensive overview of multilingualism and multilingual practices on the internet. Topics range from language choice and code-switching, the construction of multilingual practices and identities online, minority languages, translating content and researching multilingual practices online. Detailed case studies from a number of languages and regions, including Chinese, Japanese, German and Spanish, and internet platforms, including email, chatrooms, and social media, provide invaluable illustration. By the co-author of Language Online, this is key reading for all students and researchers in the area of multilingualism and new media.