Professional translation and consequently translation training involve a wide range of technological aids and translation tools. A great deal of effort has been devoted to developing and implementing features that can contribute to higher consistency, productivity and quality but less attention has been paid to the needs of learners and users. Research with professionals at the workplace suggests that there is potential to optimise the ergonomics of certain features of computer-aided translation tools. An exploratory study of the usability of two such tools with very different interfaces was carried out with students enrolled in a Master of Arts (MA) programme in translation. Quantitative measures from process monitoring software and qualitative indicators from post-task interviews highlight how students interacted with the two tools as they translated comparable source texts. The process measures and the comments suggest that the CAT tool with the leaner interface might be easier for students to use. In-depth analyses of three pairs of comparable segments support this finding, as do the evaluations of the target text segments by a separate cohort of MA students. We consider the implications of our findings in light of recent calls for improved cognitive, physical, and organisational ergonomics at the translation workplace.