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Free · No API Key · 100% Private

Using Gemini Nano
in Chrome

Gemini Nano is built directly into Chrome on supported hardware. When it works, your AI completions run entirely on your device — free, instant, and never leaving your machine.

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Note: Gemini Nano runs on your device, so it can be slower than cloud-based AI providers. For faster responses, consider using a Bring Your Own Key provider like Groq (free tier available) or OpenAI.

On this page

  1. System requirements
  2. Enable Gemini Nano in Chrome flags
  3. Verify it's working
  4. Troubleshooting
  5. What happens if it doesn't work?

1 System requirements

Gemini Nano runs locally, so your hardware matters. Chrome checks these requirements automatically before enabling the model.

Browser
Chrome 127 or later
Desktop only. Not available on mobile Chrome or other browsers.
Operating System
Windows 10/11 · macOS 13+ · Linux
ChromeOS also supported on newer Chromebooks.
Available Storage
At least 22 GB free
Chrome downloads the Nano model (~20 GB) on first use.
GPU / NPU
4 GB+ VRAM recommended
Integrated graphics usually work, but a dedicated GPU speeds inference significantly.
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If your machine doesn't meet these requirements, Donbrico Autofill AI will automatically fall back to your configured API key — no action needed on your part.

2 Enable Gemini Nano in Chrome

Gemini Nano and the Prompt API are experimental features. You need to enable two Chrome flags and then download the model before it will respond to requests.

1

Open Chrome flags

Type the following into your Chrome address bar and press Enter:

chrome://flags
2

Enable the Prompt API flag

Search for Prompt API for Gemini Nano in the flags search box, then set it to Enabled.

chrome://flags/#prompt-api-for-gemini-nano
Enables the window.ai JavaScript API so extensions can interact with Gemini Nano.
→ Set to: Enabled
3

Enable Optimization Guide (model download)

Search for Enables optimization guide on device and set it to Enabled BypassPerfRequirement. The bypass option allows download even on lower-spec hardware.

chrome://flags/#optimization-guide-on-device-model
Allows Chrome to download the Gemini Nano model to your device.
→ Set to: Enabled BypassPerfRequirement
4

Relaunch Chrome

Click the blue Relaunch button that appears at the bottom of the flags page, or close and reopen Chrome completely.

5

Trigger the model download

After relaunching, navigate to the components page to force Chrome to download the Nano model:

chrome://components

Find Optimization Guide On Device Model in the list and click Check for update. The download may take several minutes depending on your connection. The model is approximately 20 GB.

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The model download happens silently in the background. Chrome must be open and connected to the internet. Once downloaded, it stays on your device permanently.

3 Verify it's working

Once the model is downloaded, you can confirm everything is set up correctly without leaving Chrome.

Quick test via DevTools

Open any webpage, press F12 (or right-click → Inspect → Console), and paste this snippet:

const status = await window.ai.languageModel.capabilities();
console.log(status.available); // should print "readily"

The console output means:

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Once you see "readily", open the Donbrico Autofill AI extension popup. The AI status indicator in settings should show Gemini Nano · Active.

4 Troubleshooting

The console returns "no" or throws an error

Go back through the steps above and confirm both flags are enabled (not just one). Then relaunch Chrome again and wait 5–10 minutes before retesting. Chrome sometimes delays initialising the API even after the flags are set.

chrome://components shows no version for the model

Make sure you're signed into Chrome with a Google account. In some regions, the model is gated behind a Google account sign-in. Also ensure Chrome is not running through a VPN or proxy that blocks Google's download servers.

The model download is stuck

Visit chrome://components, find the Optimization Guide model, and click Check for update again. If it remains stuck, try restarting Chrome and checking for updates once more.

My machine meets requirements but it still shows "no"

5 What happens if it doesn't work?

Donbrico Autofill AI gracefully falls back to your Bring Your Own Key API key (OpenAI, Anthropic, Groq, or OpenRouter) whenever Gemini Nano isn't available. You'll never be left without AI completions.

If neither Gemini Nano nor an API key is configured, the extension will show a friendly prompt guiding you to set one up. You can always add an API key in the extension's settings panel.

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Need an API key? See the API Keys guide to get one from OpenAI, Anthropic, Groq, or OpenRouter in under 5 minutes.