This book explores creative uses of social media for informal language learning. It focuses on the underexplored area of how informal language learning adapts to technological innovations in two multimodal media-sharing platforms: TikTok and Instagram.Drawing on ecological perspectives of language learning and spatial understandings of digital technology and learning, the research reported in this book unpacks how social media technologies are used for language learning. It presents insights from a dual-level qualitative methodological design: a comparative study of public online data of social media posts collected from TikTok and Instagram, and a multiple case study based on ethnographic narrative data gathered from participants' journal entries, stimulated recall interviews, and social media posts. This book reveals the dynamic landscape of digital language learning that is being integrated into learners' everyday lives through multimodal content creation and networking.This book enriches readers' understanding of social media's role in language learning, and offers pedagogical strategies for teachers to integrate newer technologies and multimodal materials into language classrooms to enhance students' learning experiences.