Tutorial: Run a Private Mental Health AI Chatbot Locally in Your Browser Using WebLLM

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A developer tutorial published on DEV Community demonstrates how to build a privacy-focused mental health AI assistant that runs entirely within the user's browser, ensuring no data is sent to external servers. The project uses WebLLM to execute Meta's Llama-3-8B language model locally, accelerated by WebGPU and managed through a React frontend built with Vite and TypeScript. Because all inference happens on the user's device GPU, sensitive conversations are never exposed to network transmission or third-party servers. The setup requires a WebGPU-compatible GPU, Chrome 113 or Edge browser, and involves downloading a model file exceeding 5GB on first use. Encrypted chat history is stored locally via IndexedDB, and a React Context pattern is recommended to maintain a single engine instance across the application.

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