Chrome Ships Prompt API with On-Device Gemini Nano — 131 Points, 79 Comments on HN

Chrome for Developers / Hacker News (131pts, 79 comments)·medium signal

Chrome 138+ now exposes the Prompt API, a built-in JavaScript interface for running Gemini Nano on-device with zero network dependency after a one-time 1.7GB model download. The API suite includes Prompt, Summariser, Writer, Rewriter, Translator, and Proofreader — all client-side, so user data never leaves the device. Supported on Windows 10+, macOS 13+, Linux, and Chromebook Plus. For web developers, this is a fundamentally new capability: LLM inference in the browser with no API keys, no latency, and no privacy concerns. Android support coming later in 2026.