In this article, we explore the capability of speculative fiction to predict future realized technologies. We review a large set of speculative technologies introduced in speculative fiction to determine if the technologies were subsequently realized. Additionally, we explore the time between the speculated introduction and actual realization. Our dataset for analysis is built from the ‘Technovelgy’ database of speculative technologies. A realization assessment methodology is created that includes detailed rubrics to rate and quantify the predictability or realizability of speculative technologies. Three independent raters perform realization assessments for each entry. An inter-rater agreement analysis is carried out to validate the rating method. Based on the dataset of 3095 speculated technologies, 45% are labeled as ‘realized’ by at least one rater. A moderate overall agreement with a Fleiss’ Kappa of 0.57 is reached by all raters. The average time to realization of realized technologies is approximately 45 years with a standard deviation of approximately 34 years. We observe patterns in the realization of speculative technologies and analyze the underlying reasons preventing the technologies from realization. We conclude that speculative fiction predicts future technologies to such a degree that the introduction of speculative technology can be used as an input to designer decision-making.