This paper presents the methodology and results of a case study conducted on the educational software e-Sinais Web, developed to translate words and sentences from written Brazilian Portuguese into Brazilian Sign Language (Libras). The study evaluated the usability of the translation features, as well as the user and sign registration functionalities, identifying critical points in the user experience, especially among deaf users. The results indicate that e-Sinais Web fulfills its primary function of translating simple sentences, and enabling collaborative registration, with associative images. However, challenges arise in more complex tasks, such as the use of synonyms, homonyms, and sign editing, in which deaf users performed worse than hearing users.