That advice is roughly half right. Deleting the file by hand isn't the fix Google supports. The supported fix is one toggle in Chrome's settings, and it removes the file for you.
What weights.bin actually is
According to PCWorld, the file sits at this Windows path:
C:\Users\[username]\AppData\Local\Google\Chrome\User Data\OptGuideOnDeviceModel\[version number]
The version folder name looks something like 2025.8.8.1141 and will be different on your PC. The model runs entirely on your own hardware and doesn't need to contact Google's servers to work.
Google's Chrome help page lists four kinds of features that may use on-device generative AI:
- Help writing or rephrasing text
- Scam warnings
- Web page summaries
- Tab organization
Google's developer documentation adds that Chrome's built-in AI APIs (Summarizer, Writer, Rewriter, Proofreader and Prompt) run on the same kind of local model, and Chrome extensions can call them too. In plain terms, this isn't junk. It's the engine behind a set of features you may or may not use.
This isn't a new discovery, either. Back in May, Android Authority reported that a 4 GB file titled "weights.bin" had started appearing on some Chrome users' computers, even if they hadn't opted in, and an official Google statement confirmed the file runs Gemini Nano for Chrome as an on-device model. At the time, PCWorld's Ben Patterson measured the file at 4.27 GB on his Mac.
Summary: weights.bin is Gemini Nano's model file. It's big, it runs locally, and features you might use depend on it.
Why "just delete it" doesn't hold up
The October PCWorld tip tells readers to find the file in File Explorer and press Shift + Delete, which skips the Recycle Bin. It then admits that Chrome may download the file again and says to switch off on-device AI as well.
Google's own help page is stricter. It calls the Chrome settings toggle the only supported way to manage these models. It says that hunting down and deleting the model files manually isn't recommended and may not stop future downloads.
Third-party reporting agrees. Supercharge Browser notes that with on-device AI still enabled, Chrome re-fetches the full 3-4GB, and to reclaim the space for good, you disable the feature first, then the file deletes itself.
So the steps are in the wrong order. Turn on-device AI off first, and in most cases you won't need to delete anything yourself.
The supported fix, step by step
- Open Chrome on your PC.
- Click the three-dot menu at the top right and choose Settings.
- Find the On-device AI toggle and turn it off.
Where that toggle lives depends on your Chrome version:
| Source | Menu path |
|---|---|
| Google Chrome Help (current) | Settings > AI Innovations > On-device AI |
| PCWorld, October tip | Settings > AI in Chrome > On-device AI |
| Android Authority and others, mid-2026 | Settings > System > On-device AI |
If you can't find it under one heading, check the others.
What success looks like: Google says that when the setting is off, Chrome deletes the model files and won't download them again while it stays off, even if you try a feature that needs them. Several outlets saw this happen straight away. Supercharge Browser reports that the weights.bin file deletes immediately and the 3-4GB comes back with no restart required. PCWorld's tip says to click Relaunch afterwards. Google's help page doesn't mention a restart, but relaunching does no harm.
To check, open the folder again. Press Windows key + R, paste %LOCALAPPDATA%\Google\Chrome\User Data\OptGuideOnDeviceModel and press Enter. If weights.bin is gone, you're done.
Summary: Toggle first and let Chrome clean up after itself. Deleting files by hand is a last resort.
Before you start: does your PC even have it?
Plenty of readers will find no weights.bin at all, and that's expected. Google says the model and the on-device AI setting aren't available on every device. Chrome only downloads the model when your PC meets these conditions:
- Supported hardware with enough performance
- An unmetered network connection
- About 20GB of free disk space
Google's developer documentation is more specific for its built-in AI APIs:
- Windows 10 or 11
- At least 22GB free on the drive that holds your Chrome profile
- Either a GPU with more than 4GB of VRAM, or 16GB of RAM and four or more CPU cores
The same documentation says Chrome removes the model if free space drops below 10GB after the download, and may fetch it again once the conditions are met.
To see how big the model is on your machine, Google points to chrome://on-device-internals. The size changes as Chrome updates the model, so treat "4GB" as a ballpark rather than a promise. Supercharge Browser puts it at typically 3-4GB.
The setting is also per user and per device. If you share a PC, each Chrome profile keeps its own choice. Turning it off on your desktop doesn't turn it off on your laptop.
Troubleshooting: when the toggle isn't there
No On-device AI toggle anywhere. Your PC may not be eligible, in which case there's probably no model to remove. Or your Chrome build may not show the setting yet. Android Authority reported that Google began rolling out the ability for users to easily turn off and remove the model directly in Chrome settings in February. Vantaige, citing Android Authority's testing, added that the visibility of this settings page is itself gated by a flag called ShowOnDeviceAiSettings, so what you see depends on your Chrome version.
Using chrome://flags instead. Android Authority's fallback is to:
- Go to
chrome://flagsand search for "optimization-guide-on-device-model". - Set that flag to Disabled and relaunch Chrome.
- Close Chrome completely.
- Delete the leftover OptGuideOnDeviceModel folder.
Keep in mind that this method is unsupported. Supercharge Browser also warns that flags reset on Chrome updates, and the settings path is more durable.
The file came back. You almost certainly deleted it by hand while on-device AI was still on. Turn the setting off.
For IT admins: use policy, not File Explorer
Managed fleets shouldn't depend on users clicking toggles. Google's help page says Chrome Enterprise model downloads are governed by policy. Its enterprise documentation describes a Local foundational model settings policy for Chrome on Windows, Mac and Linux. The default is to download the model automatically. Admins can set it to Do not download model.
Third-party guides name the underlying policy as GenAILocalFoundationalModelSettings. Supercharge Browser describes setting it as a DWORD with a value of 1 under HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome. Check that value against Google's policy reference before you push it through Group Policy or Intune.
The trade-off and the bigger picture
Turning the setting off has a cost. Google says features that rely on these local models stop working. XDA Developers specifically mentions writing or rephrasing text and scam detection. Losing the local scam warnings matters more than losing a writing helper.
Turning it off doesn't kill all of Chrome's AI, though. Google says some Chrome AI features don't use on-device models and may keep running. If you change your mind, XDA notes you can simply re-enable the On-device AI setting and Chrome will download the model again.
The consent question is still open. Several outlets reported that Chrome downloaded the model without asking first. Google's answer is a toggle that wipes the model and keeps it off, and that's a fair fix once you know the toggle exists. On a 256GB laptop SSD, 4GB is a noticeable chunk. On a 2TB desktop, you may decide the scam warnings are worth keeping.
More desktop apps are likely to start shipping local AI models of their own. When a disk analyzer finds a mystery multi-gigabyte file, check the app's own settings for a switch before you reach for Shift + Delete.