Previous research has generally focused on understanding individual variation in either on-line processing or off-line comprehension even though some theories explicitly link difficulty in processing to comprehension problems. The goal of the current study was to examine individual variation in performance both during on-line and off-line reading measures. A battery of psycholinguistic and cognitive tests was administered to community college and university students. In addition, participants read texts in an eye-tracker and answered comprehension questions about them. Multi-level modeling was used to determine the individual-difference factors that modulated the relation between word-level characteristics (e.g., length, frequency, surprisal) and fixation durations. The analyses showed that language experience, decoding, and WMC interacted with word characteristics to influence fixation durations, whereas language experience and reasoning predicted comprehension. The results suggest that individual variation in processing does not map directly to variation in comprehension as some theories predict.