The 23rd International ACM Conference on 3D Web Technology (Web3D 2018), organized in cooperation with the Web3D Consortium, will address an extensive range of research, development, and practice related to web-based interactive 3D applications. The goal of the conference is to share innovative and creative ideas that enable development of 3D applications for a wide range of 3D environments, including the web, mobile as well as virtual and augmented reality (VR & AR) setups. Works related to various application domains, including e-commerce, education, cultural heritage, entertainment and infotainment, social media, tourism, medicine, military, industry and construction (and many others) are welcome.