MediaPipe is a framework for building cross-platform multimodal applied ML pipelines. We have previously demonstrated building and running ML pipelines as MediaPipe graphs on mobile (Android, iOS) and on edge devices like Google Coral. In this article, we are excited to present MediaPipe graphs running live in the web browser, enabled by WebAssembly and accelerated by XNNPack ML Inference Library. By integrating this preview functionality into our web-based Visualizer tool, we provide a playground for quickly iterating over a graph design. Since everything runs directly in the browser, video never leaves the user’s computer and each iteration can be immediately tested on a live webcam stream (and soon, arbitrary video).