You Have a Free AI Model Sitting in Chrome Right Now

Athreya aka Maneshwar Posted on May 30           You Have a Free AI Model Sitting in Chrome Right Now # webdev # ai # programming # node Hello, I'm Maneshwar. I'm building git-lrc, a Micro AI code reviewer that runs on every commit. It is free and source-available on Github. Star git-lrc to help devs discover the project. Do give it a try and share your feedback for improving the project. You might not have noticed, but Chrome quietly started shipping a local AI model called Gemini Nano bundled right into the browser. No API keys. No cloud round-trips. No per-token cost. It just runs on your machine. The interface to talk to it is called the Prompt API , and it landed in Chrome 138. I spent some time going through the full API surface and built a playground that lets you experiment with every feature session management, streaming, structured output, multimodal input, response prefixing, and more in one page. This post walks you through all of it. Why does this matter? On-device AI flips the usual tradeoffs: Free at runtime — the model runs on the user's hardware, not your servers Private by default — no data leaves the device once the model is downloaded Works offline — after the initial download, no network required Low latency — no round-trip to a data centre The catch is that Gemini Nano is a small model. It's great for classification, summarization, Q&A on focused content, and structured extraction. It won't replace GPT-4 for complex reasoning. Think of it as a smart, free, always-available layer you can add on top of your existing product. Enabling the API The Prompt API isn't on by default in all Chrome builds. Enable two flags: Step 1 — Go to chrome://flags/#optimization-guide-on-device-model and set it to Enabled BypassPerfRequirement . Step 2 — Go to chrome://flags/#prompt-api-for-gemini-nano and enable both the base API and the multimodal option. Relaunch Chrome. Then visit chrome://on-device-internals to check the model downlo