Just when you thought Google Chrome couldn’t get more resource-intensive and invasive, it has quietly downloaded a massive AI-related file on systems running the browser. This includes both Windows and macOS, and the worst part, users were never asked for it, nor were they even notified.
First highlighted by Alexander Hanff, aka ThePrivacyGuy, the 4GB file is eating into the storage on a large number of PCs. Given how deeply the file is buried, it’s unlikely that an average user will ever find out. Besides, for a file this big, explicit user consent is a must. I don’t recall ever allowing the download, and no one else does either.
It’s the weights.bin file
It takes up as much as 4.3GB of storage
The file in question is weights.bin, and it’s stored inside the „OptGuideOnDeviceModel“ folder within Chrome’s „Applications Support“ folder on macOS and the „AppData“ directory on Windows. The weights.bin file is associated with Chrome’s on-device AI model, Gemini Nano. According to the official documentation, the on-device model runs locally and performs functions like warning you about scam pages, helping write or rephrase text, summarizing pages, and organizing active tabs.
I checked both my systems, a Windows 11 laptop and a MacBook, and the file was only there on the former. Upon closer inspection, I found that the flag responsible for the „On-device AI“ feature in Chrome was not enabled on macOS. As soon as I changed the status for „Enables optimization guide on device“ from Default to Enabled, both the On-device AI option in Chrome settings, as well as the weights.bin file, appeared. It didn’t take more than 10 minutes.
As for its location, the weights.bin file is stored in this path:
- macOS: /Library/Application Support/Google/Chrome/OptGuideOnDevice Model/
- Windows: %LOCALAPPDATA%\Google\Chrome\User Data\OptGuideOnDeviceModel
The file size of weights.bin differs between Windows and macOS. On Windows, the file takes 3.97GB of storage, while on macOS it takes 4.27GB. That’s roughly a 300MB difference in size, not much, but still noticeable.

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Simply deleting the file isn’t enough
You have to disable „On-device AI“
If you think simply deleting the file would do the trick, that’s not how it works with the weights.bin. Chrome will re-download the file. And given how quickly it did on my MacBook after I enabled On-device AI, the reprieve will be short-lived. However, there’s a trick: disable the functionality responsible for the file.
So, to delete the roughly 4GB weights.bin file:
- Launch Chrome, click the ellipsis near the top-right corner, and select Settings.
- Navigate to the System tab and disable the toggle for On-device AI.
- As soon as you do that, Chrome will automatically remove the weights.bin file.
So, don’t delete the file, but disable the functionality that’s responsible for it. This also means that features that rely on On-device AI, like writing or rephrasing text and scam detection, will stop working. To re-download the Gemini Nano model, or the weights.bin file, simply re-enable the On-device AI setting. The download may take some time, depending on how fast your internet speed is.

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The real issue here isn’t the 4GB file but how Google downloaded it on systems without explicit user approval. Because this sets a bad precedent. ThePrivacyGuy, in his post, pointed out how Anthropic had done that a few weeks ago, but the file size was small, not even an MB. This time around, it’s 4GB.
Google, on its part, has said that Chrome only downloads the file when there’s sufficient storage space on the computer and uses it for security-related functions. This negates the need to send data to the cloud. Google also adds that Chrome automatically removes the file when the system runs low on storage. But there’s no clarity on what really constitutes a low-storage situation. Is that 20GB, 30GB, or 50GB? I, for one, try to keep at least 50–60 GB of storage free on my laptop, and this directly affects my calculation. And let’s not forget that not everyone has an unlimited internet plan. There are people still on metered connections. Was that factored in? If not, 4GB could prove costly for many of those.
At a time when many are ditching Google Chrome for open-source alternatives, due to Chrome’s reputation as a resource hog, the latest episode gives them another reason. As I said, it’s not the 4GB file itself, but the approach that matters. The PC is mine, and so is the storage on it. And neither Google nor any other application has the right to download a file this big without notifying me.

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On-device AI isn’t inherently bad
But user approval is a must
The idea of running AI models locally has gained a lot of traction in recent days, with many setting up on-device AI. For one, it offers better security, and it’s easier on the environment. Besides, Google’s Gemini Nano is pretty lightweight considering how other local AI models can take up 40–80 GB of space. Although the limited functionality explains that.
At the same time, we can’t ignore how the file got into our systems. A single prompt informing users of the download and asking for their approval would have solved the entire problem. That’s all Google really had to do. But it went ahead with an approach that led to distrust. From now on, I will be much more careful about which files apps or browsers download to my computer. It’s time companies stopped taking users for granted and started being more transparent.
Ref: https://www.xda-developers.com/chrome-quietly-installed-4gb-ai-files-on-pc-how-to-remove-them/











