AI doesn’t have to mean Python, servers, or user data leaving the device. We’ll run models in the browser with TensorFlow.js, Transformers.js, and modern Web APIs—no installs, instant demos. You’ll see real-time tasks like vision, audio, and small LLMs distilled for client-side use, plus practical limits and workarounds. We’ll end with a tiny, shippable demo pattern you can reuse. By the end, you’ll know when to go on-device vs. cloud, how to wire JS inference, and how to talk about privacy/perf trade-offs with your team.