There is a rich body of literature that details the effects of automated writing evaluation (AWE) on second language (L2) students. However, these studies mostly focus on the impact that automated feedback has on writing performance, i.e. that is, there is a dearth of research on its influence on affective factors. Hence, this study was conducted to fill this gap in the literature. The study explored the impact of Grammarly, a popular AWE tool, on English as a foreign language (EFL) students' foreign language anxiety (FLA) and learner autonomy (LA). EFL students in four separate academic writing courses (N = 58) taught by one of the researchers at a public Japanese university participated in the study. The students received training on Grammarly at the start of the Fall 2022 semester and were required to use the tool while editing their English writing during the 16-week course. Pre- and post-surveys were administered to measure the effects that Grammarly had on FLA and LA. Qualitative data in the form of written reflective reports was also collected from the participants to gain deeper insight into their perceptions of Grammarly to improve their writing. Results from the analyses indicated that Grammarly had a significant positive effect on both FLA and LA. The students also had largely positive perceptions toward Grammarly as an English writing tool. These findings have important implications for the L2 writing classroom and demonstrate that AWE can be used to reduce anxiety and promote autonomy among language learners.