Increasing the playback speed of video lectures is popular amongst students as a time saving strategy, but does this negatively impact test performance? Here, we conducted a meta-analysis to examine the effect of increasing video lecture playback speed on content test performance. A meta-regression with robust variance estimation was used to aggregate data from 110 effect sizes, stemming from 24 studies of learning from lecture videos. The results demonstrated that increasing the playback speed of lectures can negatively impact content test performance, but this cost is small (and often non-significant) for speeds 1.5 x and slower. In addition, we found no evidence of moderation of this cost by a number of theoretically important variables (e.g., test type, lecture duration). These results contribute important insights into a popular study strategy and one that is likely to be a mainstay in educational settings for years to come.