Chrome Silently Installed 4GB of AI on Your Computer: How to Find, Disable, and Delete Gemini Nano (2026)

On May 4, 2026, privacy researcher Alexander Hanff published a forensic write-up showing that Google Chrome was downloading a roughly 4GB Gemini Nano model called weights.bin onto eligible machines with no consent prompt, no notification, and an automatic redownload if you delete it. The disclosure landed on the front page of Hacker News within hours and was picked up by Snopes, TechRadar, The Verge, Engadget, The Register, and Malwarebytes the same week. This guide shows you exactly where the file lives on your machine, how to stop Chrome from pulling it again, and how to disable it across a managed fleet.

TL;DR

• Chrome downloads weights.bin (~4GB) to OptGuideOnDeviceModel/

• Started silently shipping from Chrome 138, expanded by Chrome 147

• Delete alone does not work, Chrome redownloads on next launch

• Disable in chrome://flags first, then delete the folder

• Fleets use GenAILocalFoundationalModelSettings policy (Win/Mac)

What is Gemini Nano and why is it on my computer?

Gemini Nano is Google's small on-device large language model, shipped as a 4GB binary file called weights.bin inside Chrome's user-data directory under OptGuideOnDeviceModel/. Chrome installs it automatically when your machine passes a hardware check, which is why your browser folder quietly grew by several gigabytes without you touching a setting. It powers features like Help Me Write, Tab Compare, and the on-device Prompt API.

The download is handled by Chrome's component updater. According to Alexander Hanff's forensic audit, the component identifier is {44fc7fe2-65ce-487c-93f4-edee46eeaaab} and the binary is delivered from Google's edgedl.me.gvt1.com CDN. In Hanff's controlled test, a fresh Chrome profile created on April 23, 2026 had received the full 4GB payload within 24 hours, with no human input on the machine.

The behavior was widely reported in early May 2026 by Snopes (fact-check), Malwarebytes Labs, TechRadar, The Register, and Engadget. If you are running an LLM workflow locally already, the model-layer story is documented in our run open-source AI models locally guide. Nano is the same idea, but installed without asking.

How do I check if Chrome installed Gemini Nano?

Open the OptGuideOnDeviceModel folder inside your Chrome user-data directory and look for a multi-gigabyte file named weights.bin. If the folder exists and contains a versioned subfolder (e.g. 2025.8.8.1141/weights.bin) larger than 2GB, you have it. The path differs by operating system, so use the one for your platform below.

On Windows, paste the path into File Explorer's address bar. On macOS, open Finder, press Cmd+Shift+G, paste the path, hit Enter. On Linux, use your file manager or ls -lah ~/.config/google-chrome/OptGuideOnDeviceModel/ in a terminal.

Inside the folder you will see a version directory (timestamp-style name) containing weights.bin, manifest.json, adapter_cache.bin, encoder_cache.bin, and a _metadata/ directory, per Hanff's audit. If weights.bin is around 3 to 4GB, that is Gemini Nano. If the folder does not exist, your hardware probably did not qualify for download yet, but it can still happen on a future update.

You can also verify in-browser. Visit chrome://components/ and search for "Optimization Guide On Device Model". If a version other than 0.0.0.0 is listed, the model is installed.

How do I disable Gemini Nano in Chrome?

Open chrome://flags, disable three flags (optimization-guide-on-device-model, prompt-api-for-gemini-nano, and OnDeviceModelBackgroundDownload), then relaunch Chrome. Disabling alone does not delete the existing 4GB file, but it stops the redownload after you remove it manually in the next step.

Step by step:

1. Type chrome://flags in the address bar and press Enter.

2. Search for optimization-guide-on-device-model, set the dropdown to Disabled.

3. Search for prompt-api-for-gemini-nano, set to Disabled.

4. Search for OnDeviceModelBackgroundDownload, set to Disabled (this is the one that controls the silent download).

5. If the multimodal variant flag is present (prompt-api-for-gemini-nano-multimodal-input), disable it too.

6. Click Relaunch at the bottom of the page.

Then visit chrome://settings/ai. Toggle off any "On-device AI" or "Help Me Write" options that appear. Per Android Authority's reproduction, the visibility of this settings page is itself gated by a flag called ShowOnDeviceAiSettings, so what you see depends on your Chrome version.

Affected Chrome versions: per gHacks, the silent component-updater pull began with Chrome 138 in 2025, expanded around Chrome 147 (when the on-device API became generally available for extensions), and a privacy disclosure line was removed in Chrome 148. If you are on 147 or newer, assume you are affected unless you confirm otherwise via chrome://components/.

How do I permanently delete the 4GB and stop re-download?

Close Chrome completely, delete the OptGuideOnDeviceModel folder, then relaunch with the three flags above already disabled. If the flags are still enabled, Chrome will repopulate the folder on next launch, so the disable step must happen first. Confirm success by reopening the folder path and checking that the file does not return after a restart.

Windows (PowerShell, run as your user, Chrome closed):

Stop-Process -Name "chrome" -Force -ErrorAction SilentlyContinue
Remove-Item -Recurse -Force "$env:LOCALAPPDATA\Google\Chrome\User Data\OptGuideOnDeviceModel"

macOS (Terminal, Chrome quit):

osascript -e 'quit app "Google Chrome"'
rm -rf "$HOME/Library/Application Support/Google/Chrome/OptGuideOnDeviceModel"

Linux (terminal, Chrome closed):

pkill -f "chrome" 2>/dev/null
rm -rf "$HOME/.config/google-chrome/OptGuideOnDeviceModel"

After Chrome relaunches, wait 5 minutes, then re-check the folder path. If it stays empty (or the weights.bin file does not reappear), the disable worked. If a fresh weights.bin shows up, one of the flags reverted (Chrome resets some flags on major updates) and you need to disable them again. For Windows users who want a tamper-proof block that survives updates, the Group Policy approach in the IT section below is more reliable.

A note on settings persistence: chrome://flags toggles are not guaranteed to survive a Chrome major version bump. PCWorld's coverage and Pureinfotech's Windows 11 guide both recommend re-checking after Chrome updates because the flags can flip back to default. The registry/policy method described in the IT section is the only solution that survives every Chrome release without monitoring.

Will disabling Gemini Nano break Chrome features?

No critical Chrome features depend on it. Disabling Gemini Nano turns off optional on-device AI features such as Help Me Write in text fields, Tab Compare, Tab Group auto-naming, and any extension or web app that calls Chrome's experimental Prompt API (window.ai / Translator / Summarizer JavaScript APIs). Page rendering, sync, sandboxing, password manager, and all core browsing functionality are untouched.

What you lose if you disable it:

• Help Me Write: AI rewrite suggestions in text fields and form inputs

• Tab Compare / Tab Group AI: auto-naming and side-by-side comparison

• window.ai JavaScript API: any web app or extension calling the on-device Prompt API stops working in your browser

• On-device Summarizer / Translator / Writer APIs: same story, third-party experimental integrations break

If none of those phrases mean anything to you, you do not use these features, and disabling Gemini Nano costs you nothing. Cloud-based AI in Chrome (anything that talks to Google's servers, like AI Overviews in Search) is unaffected because that runs server-side, not from weights.bin.

How do I prevent this on a fleet of machines (IT angle)?

Use the GenAILocalFoundationalModelSettings policy on Windows 11 Pro/Enterprise/Education or in a macOS managed-preferences profile, set to Disabled (value 1). According to Chrome Enterprise's policy documentation, when set to 1 the browser will neither download the model nor keep an existing copy: it gets deleted on next launch.

Windows registry (single machine or via GPO push):

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome]
"GenAILocalFoundationalModelSettings"=dword:00000001

For Group Policy on Windows 11 Pro/Enterprise (KB5053598 March 2025 or later, per Windows Forum coverage):

1. Install the latest Google Chrome ADMX templates.

2. Open gpedit.msc, navigate to Computer Configuration > Administrative Templates > Google > Google Chrome > Generative AI.

3. Open Settings for generative AI local foundational model, set to Enabled, choose Disabled (1) from the dropdown.

4. Run gpupdate /force, then relaunch Chrome.

macOS managed preference (com.google.Chrome.plist):

sudo defaults write /Library/Preferences/com.google.Chrome GenAILocalFoundationalModelSettings -int 1

Or push the same key through MDM (Jamf, Kandji, Mosyle, Intune for Mac) as part of your Chrome configuration profile, alongside whatever managed-policy bundle you already deploy.

The same policy also covers Microsoft Edge starting with Edge 132, per Windows admin coverage of the GenAILocalFoundationalModelSettings rollout. If your fleet runs both browsers, push it to both.

For teams that prefer running their own on-device model rather than Google's, the cleaner architecture is to disable Nano and self-host a model you actually chose. See our Nous Hermes 4 self-hosted setup for the open-weight side of that picture, and our OpenClaw setup guide for the agent layer on top.

FAQ

Is the 4GB Gemini Nano download a security risk?

It is not a known malware vector, the file is signed by Google and delivered over the official Chrome component updater. The concerns raised by Alexander Hanff's disclosure are about consent, disk usage, and bandwidth: 4GB pushed to potentially hundreds of millions of devices with no opt-in, no notification, and automatic redownload after deletion. Hanff also argues the silent install may conflict with the EU ePrivacy Directive's storage-on-device clause and the GDPR's transparency requirements, but no regulator has ruled at time of writing.

Why does Chrome redownload weights.bin after I delete it?

Because the on-device model is enabled by default in Chrome's flags, and Chrome's component updater treats it as a required component, like the Widevine DRM module or the safe-browsing list. Deleting the folder while the flag is on tells Chrome the component is missing, and the updater repairs it on next launch. Disabling optimization-guide-on-device-model, prompt-api-for-gemini-nano, and OnDeviceModelBackgroundDownload is what tells the updater to stop trying.

Does Brave, Edge, Firefox, or Arc also do this?

Microsoft Edge has the same plumbing and is covered by the same GenAILocalFoundationalModelSettings policy from version 132 onward. Brave and Arc are both Chromium forks but ship their own component-updater config and as of May 2026 do not auto-install Gemini Nano. Firefox is not Chromium, has no Gemini Nano integration, and is not affected. If you want the silent-AI risk surface gone entirely, switching browsers is the simplest path, our team uses Firefox for daily browsing and Chrome only for the few tools that require it.

Can I tell if Chrome already ran Gemini Nano on my data?

Not directly from the file system alone, the model runs on-device so there is no server-side log to check. What you can confirm is whether features that use it were active. Visit chrome://settings/ai and look at the toggle state, check chrome://components/ for the model version, and check Help Me Write history in any Google Docs or Gmail tab if you use them. The 4GB file being present does not mean the model ran on your text, it means it was loaded and ready.

Will Google fix the silent-install behavior?

Google began rolling out an in-settings disable toggle in February 2026 (before Hanff's May disclosure), and after the disclosure was reported by Snopes, The Verge and others, Chrome quietly removed a "no data sent to Google" line from its on-device AI settings page in version 148. As of May 11, 2026, the default-on, silent-download behavior persists for users who do not actively toggle it off. Watch the Chrome release notes and chrome://flags defaults on each major update.

Is there an equivalent to Gemini Nano I can run that I actually control?

Yes, open-weight on-device models exist that you choose and update yourself. The two practical paths are: (1) run a small Apache 2.0 model via Ollama or LM Studio on your own machine for chat and tools, or (2) for agentic workloads, self-host something like Nous Hermes 4.3 36B per our self-hosted Hermes guide. The difference versus Chrome's Nano is consent: you decide which model, when it downloads, and where it lives.

References

1. Alexander Hanff, "Google Chrome silently installs a 4 GB AI model on your device without consent" (May 4, 2026) thatprivacyguy.com

2. Snopes fact-check on the Chrome 4GB AI install snopes.com

3. Malwarebytes Labs, "Google Chrome's silent 4GB AI download problem" malwarebytes.com

4. TechRadar, "The climate costs are insane: why Chrome users are outraged over a forced 4GB Gemini AI update" techradar.com

5. The Register, "Chrome silently installs a 4 GB local LLM on your computer" theregister.com

6. Engadget, "Chrome downloads a 4GB AI file without user consent, researcher alleges" engadget.com

7. gHacks Tech News, "Google Chrome Is Silently Downloading a 4GB Gemini Nano AI Model" ghacks.net

8. Android Authority, "How to delete Chrome's weights.bin file and disable Gemini Nano" androidauthority.com

9. Pureinfotech, "Stop Chrome from silently downloading Gemini Nano AI model on Windows 11" pureinfotech.com

10. Chrome Enterprise policy, GenAILocalFoundationalModelSettings chromeenterprise.google

11. PCWorld, "Chrome silently downloads a 4GB AI model. Here's how to remove it" pcworld.com

Related from Vantaige

• Run Open-Source AI Models Locally: A Battle-Tested Guide (2026)

• Nous Hermes 4: The Self-Hosted Open-Weight Agent Brain (2026)

• How to Get Cited by AI in 2026: The Practical GEO Playbook

• OpenClaw Setup Guide: Secure Config and Automation Hacks