Google Chrome can now download AI models directly to your Windows PC, and you might not realize they’re there until you start investigating what’s taking up your storage.

While checking the latest stable version of Google Chrome on one of our Windows PCs, I found a large weights.bin file stored inside Chrome’s User Data folder. In my case, the file was taking up roughly 4GB of storage.

This isn’t malware or a suspicious Chrome extension. It’s connected to Chrome’s on-device AI capabilities.

Google itself confirms that Chrome may download generative AI models in the background so that supported AI-powered browser features are ready to work locally on your computer.

The good news is that Chrome now provides a simple setting to disable these on-device models. You can also remove the already-downloaded files to reclaim the disk space.

In this guide, I’ll show you how to check whether Chrome has downloaded an AI model on your Windows PC, find out how much storage it is using, remove it, and prevent Chrome from downloading it again.

Quick answer: Open Chrome > Settings > System and turn On-device AI off. If the model has already been downloaded, you can then remove its files from Chrome’s User Data directory to reclaim the storage.

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Why Is Google Chrome Downloading AI Files?

Google has been steadily adding AI features to Chrome, but not all of them rely entirely on cloud processing.

Some capabilities can use on-device AI models, meaning the AI model itself is downloaded and stored on your computer.

According to Google, on-device generative AI models can be used for features including writing or rephrasing text, scam warnings, page summarization, and tab organization.

Because the model runs locally, Chrome needs to download the required model files before those features can work.

Google says these models may be downloaded in the background so supported features remain ready for use.

That explains why some users may discover several gigabytes of Chrome data even though they never manually downloaded an AI model themselves.

Prefer watching instead? In the video below, I show exactly where Chrome stores its on-device AI files and how to disable the feature to prevent future downloads.

This placement gives readers the explanation first and then offers the video before the step-by-step tutorial.

How Much Storage Does Chrome’s AI Model Use?

There isn’t one fixed file size that applies to every Chrome installation.

On the Windows PC I tested, the weights.bin file was approximately 4GB.

The exact size can change as Google updates its models and depending on the on-device capabilities available to your installation.

Chrome’s developer documentation specifically says that the exact Gemini Nano model size can vary as Chrome updates the model.

You can also enter:

chrome://on-device-internals

in Chrome’s address bar to inspect information about the currently installed on-device model.

So if you’ve seen claims that Chrome always downloads 20GB of AI data, don’t assume that your installation is using that much. Check your own Chrome installation first.

How to Check If Chrome Has Downloaded AI Files on Windows

You can check the Chrome User Data directory manually.

1. Open File Explorer

Press Windows + E or open File Explorer from the Start menu.

Select This PC so you can see the drives connected to your computer.

2. Enable Hidden Items

Chrome’s files are stored inside the AppData directory, which Windows hides by default.

In File Explorer, click: View > Show > Hidden items

Make sure Hidden items is checked.

3. Open Your Windows User Folder

Navigate to:

C:\Users\YourUserName\

Replace YourUserName with the profile name you use on your PC.

If Windows is installed on another drive, open that drive instead of C:.

4. Open Chrome’s User Data Folder

Now navigate through these folders:

AppData > Local > Google > Chrome > User Data

The complete path should look similar to:

C:\Users\YourUserName\AppData\Local\Google\Chrome\User Data\

5. Find OptGuideOnDeviceModel

Scroll through the folders and look for:

OptGuideOnDeviceModel

This directory is associated with Chrome’s on-device model.

If the folder doesn’t exist on your PC, Chrome may not currently have the corresponding model downloaded there.

6. Open the Version Folder

Open OptGuideOnDeviceModel.

Inside, you should see a folder with numbers representing the installed model/component version.

Open it.

7. Look for weights.bin

Inside the folder, look for:

weights.bin

This is the important file.

Right-click it and select Properties to check how much storage the file is consuming.

On my test PC, it was around 4GB.

If you’re trying to figure out why Chrome is suddenly using several gigabytes of additional disk space, this is one place worth checking.

How to Stop Chrome From Downloading On-Device AI Models

Finding the file is only half of the process.

If you simply remove the model while Chrome’s on-device AI functionality remains enabled, Chrome may need the model again when those capabilities are used.

Google now provides an official control for managing these models.

1. Open Google Chrome

Launch the latest version of Chrome.

2. Open Chrome Settings

Click the three-dot menu in the upper-right corner. Select Settings

3. Open System Settings

From the menu on the left, select System

4. Turn Off On-device AI

Look for the On-device AI option. Toggle it OFF.

That’s it.

According to Google, turning this setting off disables the on-device generative AI models used by features that depend on them.

How to Delete Chrome’s Downloaded AI Model and Free Up Space

Once you’ve disabled On-device AI, you can reclaim the disk space occupied by the downloaded model.

Close Chrome first.

Return to:

C:\Users\YourUserName\AppData\Local\Google\Chrome\User Data\OptGuideOnDeviceModel\

You can then remove the downloaded model files.

Google confirms that deleting its on-device generative AI models frees up storage space.

However, there’s an important trade-off.

Features that require the deleted on-device model will no longer work. If you enable On-device AI again, Chrome can download the required models again.

So don’t delete the model if you actively use Chrome features that depend on local AI processing.

What Happens If You Disable On-device AI in Chrome?

Turning off On-device AI doesn’t mean that every AI-related feature across Google Chrome and Google services disappears.

It specifically affects Chrome features that depend on its locally stored generative AI models.

Google notes that some Chrome AI features do not rely on these on-device generative models and may continue working even after the local models are removed.

In other words:

On-device AI OFF = Chrome stops using the locally installed generative AI models for features that require them.

It isn’t necessarily a master switch for every AI feature connected to Chrome or Google.

Should You Delete Chrome’s AI Model?

That depends on how you use Chrome.

If you have plenty of SSD space and regularly use Chrome’s on-device AI features, keeping the model installed may make sense.

But if you don’t use those features and you’re trying to reclaim storage—particularly on a laptop with a 128GB, 256GB, or 512GB SSD—several gigabytes can be significant.

Personally, if I weren’t using the features that require the model, I’d rather reclaim the space.

The important part is that Chrome gives you a choice: you can turn On-device AI off and remove the local model, or leave it enabled if you want the supported AI features.

Frequently Asked Questions

Why is Chrome downloading AI files?

Chrome downloads on-device generative AI models so supported AI features can perform certain tasks locally on your computer. Google says these models may be downloaded in the background to keep those features ready for use.

What is OptGuideOnDeviceModel in Chrome?

OptGuideOnDeviceModel is a directory within Chrome’s User Data folder associated with its on-device model component. It can contain the model files Chrome uses for local AI functionality.

What is weights.bin in Google Chrome?

weights.bin contains model weight data used by Chrome’s on-device AI model. Because AI models contain large numbers of parameters, these files can consume several gigabytes of disk space.

Is OptGuideOnDeviceModel malware?

No. Finding the legitimate OptGuideOnDeviceModel directory within Chrome’s normal User Data directory does not by itself indicate malware. It is associated with Chrome’s on-device model functionality.

Can I delete weights.bin?

If you don’t want to use Chrome features that depend on the on-device model, you can disable On-device AI and remove the downloaded model to reclaim storage.

Google warns that features requiring the model won’t work after the model is removed.

Will Chrome download the AI model again?

It can if you enable On-device AI again. Google says turning the setting back on allows Chrome to download the AI models required by supported features.

How can I check Chrome’s on-device AI model?

Open Chrome and enter: