Social media platforms have altered how social interactions take place online. This new era of user practices, micro-communication cultures, bots, and an increasing algorithmic shaping of sociability, opens up new research endeavours to understand how racism articulates on social media platforms. Research points to the need of studying racism and other forms of systemic oppression as the result of user practices and technological mediation. In the realm of social media, key technological features - such as anonymity, interactivity, connectivity and datafcation - are tactically exploited to create new modalities of ‘platformed racism’. However, access to data is gradually becoming scarce, as platforms increasingly close of their Application Programming Interfaces (APIs), while new opaque platforms, such as WhatsApp and WeChat, pose challenges for empirical research. This article presents a literature review of 113 scholarly articles on racism and social media published between 2014 and 2018, collected through Google Scholar and Web of Science (of an initial sample of 270 articles). The article frst examines the geographical scope and overall methodologies described in the literature. Secondly, the article presents an in-depth analysis of the methodological and ethical challenges of studying racism on social media. Based on this analysis, the article critically discusses the overall limitations of the feld, possibilities of overcoming these as well as future problems posed by increasing opacity and social media companies’ questionable arrangements to collaborate and support research.