The use of experiments in the undergraduate economics classroom has been shown to have pedagogical value in increasing student learning and engagement, but the startup costs of adopting classroom experiments can be high for instructors. This article serves as a guide to adoption for the first-time user of computerized (online) classroom experiments. It covers the three major online classroom experiment platforms: MobLab, classEx, and VeconLab, and compares the use of online platforms to manual implementation of experiments. It also includes a discussion of which characteristics of online platforms determine their suitability for different classroom contexts and learning modalities and compares the three major platforms along these dimensions.