Learners' varied Web 2.0 and informal online learning practices and subsequent language acquisition would appear to have multiple and complex links to autonomy, affecting L2 autonomy, learner autonomy and general autonomy. If we consider language learning through the lens of complex dynamic systems theory (CDST; Larsen-Freeman & Cameron 2007, De Bot, Lowie & Verspoor 2007), autonomy (of various types) and L2 proficiency and digital literacy would all seem to be acting as attractor states (Hiver, 2015), creating movements potentially leading to virtuous or vicious circles in consecutive feedback loops. Drawing on examples from the online informal learning of English (OILE) such as watching foreign language series, participating in online forums and multi-player online gaming, we attempt to provide a complex dynamic systems analysis of the autonomy and proficiency interactions at play in these types of learning situations.