In this paper, we explore whether there exist ‘contrast’ features that help recognize if a text variety is a genre or a domain. We carry out our experiments on the text varieties that are included in the Swedish national corpus, called Stockholm-Umeå Corpus or SUC, and build several text classification models based on text complexity features, grammatical features, bag-of-words features and word embeddings. Results show that text complexity features and grammatical features systematically perform better on genres rather than on domains. This indicates that these features can be used as ‘contrast’ features because, when in doubt about the nature of a text category, they help bring it to light.