Previous reading research on incidental word learning as product and process has largely employed computer- or paper-based delivery methods. The present study uses a novel combination of offline and online measures to examine the effects of mobile media (mobile phone and tablet) compared to traditional media (paper and computer) on incidental L2 word learning from reading at three stages: the acquisition outcome, the acquisition process, and the posttest recall. One hundred fifty-six participants were assigned to one of the four media conditions with their eye movements recorded. We examined the acquisition outcome using form recognition, meaning recognition, and meaning recall posttests. We examined the acquisition process using summed first fixation duration, summed gaze duration, and summed fixation time. We used response time to examine the posttest recall. Our results show that mobile-assisted reading yielded an equivalent performance in word learning accuracy, allocated visual attention, and response time compared with paper-based reading that still presents a small advantage. Lower performance in one dimension of accuracy and two dimensions of attentional allocation suggest less efficiency in word learning from computer-assisted reading. This study presents a new research direction and cognitive evidence of the effectiveness of mobile-assisted language learning in word learning. We critically discuss the limitations of this study and provide suggestions for future research.