The vulnerability of statistical learning has been demonstrated in reading difficulties in both the visual and acoustic domains. We examined segmentation abilities of adolescents with three different levels of reading fluency in the acoustic verbal and visual nonverbal domains. We applied online target detection tasks, where the extent of learning is reflected in differences between reaction times to predictable versus unpredictable targets. Explicit judgments of well-formedness were also elicited in an offline two-alternative forced choice task. A significant online learning effect was observed in all groups in both domains, and online patterns were similar in participants with low, medium and high reading fluency. On the offline measures, all groups were at chance in the visual, but not the verbal domain. These findings suggest that there is no robust statistical learning impairment associated with reading problems either in the visual or the acoustic domain in adolescents. Results also imply that offline measures may mask learning abilities, and measuring learning online can provide a deeper understanding of the learning process and of its potential deficits.