The Web is an open and dynamic medium that offers great opportunities for accessing and extracting data for migration research. These opportunities are signposted by concepts such as big data or open data, which incite researchers to envision the World Wide Web as a gigantic network of all kinds of datasets. However, many migration scholars are not familiar with the wealth of web-based resources or lack the operational expertise for actually leveraging these data for their research purposes. This chapter aims to highlight the benefits that migration researchers can obtain when embracing data science. After introducing key concepts, we first describe a range of data sources (theme-specific and generalist data banks, public data repositories, and search engines) of outstanding relevance for migration studies. Then, we explain the various techniques by means of which web-based datasets can be retrieved and stored. The chapter concludes by summarizing the advantages and potentialities of mining the Web for migration research, as well as related challenges and limitations.