The article discusses the challenges and solutions for conducting online behavioral experiments, focusing on the Gorilla Experiment Builder (gorilla.sc). Online research allows access to large and diverse samples, but technical barriers, such as browser timing issues, can affect accuracy and reliability. JavaScript is a key tool for online experiments, but its dynamic nature can lead to timing inaccuracies. The Gorilla Experiment Builder is a platform designed to address these issues, offering a user-friendly interface for creating and deploying experiments. It has been tested with various participant groups, settings, and equipment, demonstrating its ability to run reaction-time-sensitive tasks. The platform uses techniques like caching and requestAnimationFrame() to ensure accurate timing. The article also discusses the limitations of online research, such as variability in internet connections and browser performance, and suggests solutions like preloading resources and using standardized tools. The Gorilla Experiment Builder is compared to other tools, highlighting its advantages in terms of usability and reliability. The article includes case studies showing the platform's effectiveness in different settings, including schools and public events. The results of two experiments are presented, showing that the Gorilla platform can accurately measure reaction times and accuracy in both children and adults. The study demonstrates that the platform can reliably conduct online experiments, even in varied conditions. The article concludes that the Gorilla Experiment Builder provides a valuable tool for researchers seeking to conduct online behavioral studies with high accuracy and reliability.The article discusses the challenges and solutions for conducting online behavioral experiments, focusing on the Gorilla Experiment Builder (gorilla.sc). Online research allows access to large and diverse samples, but technical barriers, such as browser timing issues, can affect accuracy and reliability. JavaScript is a key tool for online experiments, but its dynamic nature can lead to timing inaccuracies. The Gorilla Experiment Builder is a platform designed to address these issues, offering a user-friendly interface for creating and deploying experiments. It has been tested with various participant groups, settings, and equipment, demonstrating its ability to run reaction-time-sensitive tasks. The platform uses techniques like caching and requestAnimationFrame() to ensure accurate timing. The article also discusses the limitations of online research, such as variability in internet connections and browser performance, and suggests solutions like preloading resources and using standardized tools. The Gorilla Experiment Builder is compared to other tools, highlighting its advantages in terms of usability and reliability. The article includes case studies showing the platform's effectiveness in different settings, including schools and public events. The results of two experiments are presented, showing that the Gorilla platform can accurately measure reaction times and accuracy in both children and adults. The study demonstrates that the platform can reliably conduct online experiments, even in varied conditions. The article concludes that the Gorilla Experiment Builder provides a valuable tool for researchers seeking to conduct online behavioral studies with high accuracy and reliability.