Immersive Virtual Reality (IVR) offers promising opportunities for education and training, yet its broader adoption in web-based learning environments remains limited due to performance constraints and the lack of support for industry-standard game engines. This paper presents the WebXR Interaction Toolkit (WebXRIT), a lightweight framework for creating WebXR-based training applications in Unity. Designed to provide essential interaction functionalities while minimizing runtime overhead, WebXRIT integrates with the open-source WebXR Export plugin and follows Unity’s component-based interaction architecture. To evaluate its runtime performance, we compared WebXRIT with Unity’s default XR Interaction Toolkit (XRIT) across twelve valid build configurations (varying editor version, render pipeline, and color space) using the Meta Quest 3. Results show that WebXRIT consistently outperforms XRIT, achieving significantly higher frame rates in multiple configurations, with mean values up to 78 FPS, exceeding the recommended threshold for native IVR applications. These findings highlight the potential of the WebXRIT to enable performant and accessible IVR training applications on the web. Future work will extend our toolkit with support for hand tracking, AR interaction, and additional navigation and UI components.