The present study examined the effect of technology-based writing instruction on writing outcomes using meta-analytic methods. Additionally, this study investigated whether characteristics of study, sample, and outcome moderated the effect of technology-based writing instruction. Six studies were coded resulting in 11 extracted effect sizes. Results revealed that the weighted average effect size for technology-based writing instruction was 0.28, suggesting an educationally relevant and impactful effect of education technology on writing outcomes. Several moderators were included in this meta-analysis, but did not significantly influence effect sizes. One exception was learning disability (LD) status; however, these results should be interpreted with caution as only one study included an LD sample. Overall, these results support previous research and provide knowledge of the populations that are potentially impacted by technology-based writing instruction. Previous literature suggests technology-based writing instruction may supplement teachers' efforts to deliver instruction and provide practice time to students, affording students extra opportunities to engage with writing both in and out of the classroom; however, more research is required to determine the exact mechanisms through which technology may impact writing skills. Recommendations for reporting techniques and directions for future research in development and implementation of technology-based writing instruction are discussed.