Turn on Chrome's built-in AI for NanoFocus
NanoFocus uses Chrome's built-in Summarizer API, powered by the locally installed Gemini Nano model, to summarize articles entirely on your device. If your browser already has the API enabled, NanoFocus will work the moment you install it. If not, this guide walks you through the one-time setup, which takes about five minutes plus a model download.
System requirements
Chrome's built-in AI runtime has hardware and OS minimums set by Google. Before you start, confirm your machine meets them.
Chrome's on-device AI is also available on Chromium-based browsers that ship the Summarizer API (Edge, Brave, Arc, Opera). Firefox and Safari don't currently expose a comparable on-device LLM API, so NanoFocus is Chromium-only.
Check whether Chrome AI is already on
If you've used another Chrome AI feature recently (like Help Me Write, or another extension that uses Gemini Nano), you may already have the model installed and the flag enabled. Quick check:
- Open a new tab and go to
chrome://components - Look for an entry called Optimization Guide On Device Model
- If the version is something like
2024.x.x.xxxx(not0.0.0.0) and Status is Up-to-date, the model is installed.
If that's the case, install NanoFocus and try summarizing any article. If it works on the first try, you can skip the rest of this guide. If you still see a "Gemini Nano not supported on this device" message in the side panel, follow the steps below.
Enable the Summarizer API flag
In a new tab, paste this URL into the address bar and press Enter:
chrome://flags/#summarization-api-for-gemini-nano
This opens Chrome's experimental flags page filtered to the Summarizer API entry.
Use the dropdown next to "Summarization API for Gemini Nano" and choose Enabled. (If you see options like "Enabled BypassPerfRequirement", pick that one if your machine is below Google's official hardware bar but you still want to try.)
In the same flags page, search for or paste this URL:
chrome://flags/#optimization-guide-on-device-model
Set this to Enabled BypassPerfRequirement (or just "Enabled" if BypassPerfRequirement isn't shown). This tells Chrome to download the on-device model regardless of your hardware tier.
Click the blue Relaunch button at the bottom of the flags page. Chrome will close and reopen with the flags applied.
Download the Gemini Nano model
Now Chrome needs to download the Gemini Nano model itself. The download is roughly 22 GB, happens in the background, and only happens once.
Open chrome://components and find Optimization Guide On Device Model. Click Check for update. The status should change to "Downloading...".
If the status stays at "0.0.0.0" after several minutes, restart Chrome once and try again. Chrome occasionally needs a nudge before it starts the download.
The download takes 10 to 60 minutes depending on your connection. You can keep using Chrome while it runs. When the version goes from 0.0.0.0 to a real version number and the Status reads Up-to-date, you're done.
Verify the setup works
Install NanoFocus from the Chrome Web Store if you haven't already. Pin the icon to your toolbar for quick access.
Navigate to a substantial article on any site (Wikipedia, a news site, a blog post, anywhere). Click the NanoFocus icon to open the side panel.
Pick a mode (TLDR is the fastest demo), pick a length, click Summarize. The summary should stream in within seconds. The footer of the side panel will read "Summarized on-device".
Troubleshooting
Side panel says "Gemini Nano will download on first run"
This is normal on the very first summarization after install. Chrome may need to finalize the model assets. Wait up to a minute, then click Summarize again. If it persists, check chrome://components and confirm the Optimization Guide On Device Model is at a real version, not 0.0.0.0.
Side panel says "Gemini Nano not supported on this device"
One of the flags isn't enabled, or your hardware doesn't meet the minimums. Re-check Steps 1-3 of this guide and try the BypassPerfRequirement option if available. If you're on a low-VRAM machine and BypassPerfRequirement still doesn't work, the model genuinely can't run on your hardware.
Summarize button does nothing
Open Chrome DevTools on the page (F12), check the Console tab for errors. The most common cause is a page that NanoFocus can't read (a Chrome internal page, a PDF viewer, an extension page). Try a regular HTML article.
Summary takes more than 60 seconds
NanoFocus times out single Nano calls after 60 seconds. On long articles (over a few thousand words), summarization runs in chunks and you'll see "Summarizing chunk 3 of 11..." status updates. If a single chunk hangs past 60 seconds, you'll get an error message and can retry. This is rare but can happen if Chrome's model is under load.
Free-tier daily cap hit
The free tier is capped at 5 summaries per day. Pro is a one-time $9.99 unlock for unlimited use, all four modes, all three lengths, history, compare, auto-summary, and Markdown export. Click "Unlock Pro" in the side panel to upgrade via ExtensionPay.
What stays on your device
Article text, your summaries, your history, your preferences, and your auto-summary domain list all live in chrome.storage on your machine. Nothing is transmitted to any NanoFocus server, because NanoFocus does not operate any servers. The only network call the extension makes is a license-status check to ExtensionPay (so the daily cap and Pro features work correctly); that call carries no article content.
Read the full Privacy Policy for the complete disclosure.