Vocabulary is an important component that students must master in order to master other language skills, such as reading, writing, listening, and speaking. Vocabulary learning can be effectively done through reading stories. A popular example is Alternative Universe (AU), a setting for a work of fan fiction found on Twitter or X. Utilizing a qualitative research design, this study investigated students' perception of reading short stories in AU for vocabulary development. The participants were 78 students consisting of 36 senior high school (SHS) students and 42 university students. Data was collected through questionnaires. The findings show that most respondents were familiar with and engaged in reading AU stories. The participants had a positive perception of reading AU stories because it helped them discover new words, recall previously learned vocabulary, and improve their reading skills. Therefore, it was concluded that AU stories can be an effective tool to increase vocabulary among EFL students.