["Journal of Computer Assisted Learning, Volume 42, Issue 5, October 2026. ", "\nABSTRACT\n\nBackground\nResearch has investigated how AI‐generated feedback affects L2 writing development. Less attention has been paid, however, to students' emotional experiences when using generative AI tools in informal language learning or to how these experiences relate to writing outcomes.\n\n\nObjectives\nThis study examined EFL learners' writing performance and emotional experiences in relation to their use of AI‐generated feedback beyond the classroom.\n\n\nMethods\nGuided by the broaden‐and‐build theory, this quasi‐experimental mixed‐methods study involved 110 Chinese EFL learners enrolled in an Academic Writing course in northern China. Participants were recruited from two intact Academic Writing classes, with one existing class assigned to the experimental group (n = 55) and the other existing class assigned to the control group (n = 55). Both groups received the same classroom instruction on academic writing. Compared with the control group, the experimental group received additional guidance on how to use ChatGPT to generate out‐of‐class writing feedback and engaged in self‐directed AI‐supported writing revision outside the classroom. The final writing assessment was conducted in class under comparable conditions for both groups. Writing performance was evaluated using an analytic rubric, and learners' anxiety, enjoyment and boredom were measured by established self‐report scales. Open‐ended responses were analysed inductively.\n\n\nResults and Conclusions\nThe experimental group achieved significantly higher writing scores and reported significantly lower anxiety, boredom and enjoyment than the control group. Qualitative data showed that learners found AI‐generated feedback helpful for organising ideas and improving language use; however, they also expressed concerns about communication issues and over‐dependence on AI tools. These findings contribute to research on AI‐mediated informal digital learning of English and suggest that AI‐generated feedback may be associated with both L2 writing development and learners' emotional experiences.\n\n"]