My 2020 M1 MacBook Air still runs well, but conserving hard drive space as years of files, media, and software accumulate is a continual challenge. So I was miffed when I read security researcher Alexander Hanff’s May 4 report that Google Chrome has been automatically downloading an over-4GB AI model called Gemini Nano onto everyone’s computer, without asking for consent or providing notification. Chrome is not my main browser (I’m a Firefox diehard), and Gemini is not my main AI (that would be Claude). I’m paying a hefty hard-drive tax for something I don’t use.
Simply deleting the file, called weights.bin, is useless. Chrome just downloads it again. And most of the advice on how to get around that doesn’t work—at least in my extensive testing.
A lot of what I discuss here applies to both Macs and PCs, but the techiest advice is for Macs, as that’s where it’s been most studied and where I was best able to test it.
Google added Gemini Nano in version 126 of Chrome, released in June 2024. But Hanff’s extensive forensic reporting of how it operates on a Mac brought the issue center stage this week, spawning a raft of tech advice articles. In response, Google issued a short statement saying that, in fact, there is a simple toggle in Chrome to disable and remove Gemini Nano.
None of that advice may actually work on your system.
Gemini Nano is designed to speed up in-browser AI features such as improving writing and editing by running jobs on your computer, rather than sending your data to Google’s cloud. You may find this useful, and be happy to keep Gemini Nano installed. But if you do want to ditch it, you may have to take more complicated steps than what Google and the press have been telling you.
What didn’t work
A statement Google sent to me and the rest of the media, reads, in part:
“In February, we began rolling out the ability for users to easily turn off and remove the model directly in Chrome settings. Once disabled, the model will no longer download or update. More details in our help center article.”
It took nearly two years for Google to start “rolling out” the kill switch, and it appears to be a slow roll. I’ve examined the latest version of Chrome (V 148) in two installations on macOS 26 and one on Windows 11. Only the Windows version has the new toggle, called “On-device AI.” This does disable and remove the model.
As for my Mac, a Google spokesperson declined to say anything beyond the statement or offer a sense of when I might get the upgrade. I’m not alone. Some tech journalists who picked up the story did not have it. Now the internet is buzzing with work-arounds for removing Gemini Nano that don’t actually work—at least not on my two macOS setups.
The advice being circulated centers around Chrome “flags” that turn features on or off. You can get there by typing “chrome://flags” in the browser’s address bar. The common advice is to search for and select “Disabled” for a feature called:
“Enables optimization guide on device
Enables the optimization guide to execute models on device. – Mac, Windows, Linux, ChromeOS”
I made that change and also disabled flags for the six Gemini Nano services (including help for writing, rewriting, proofing, and summarizing text). But a fresh Gemini Nano quickly appeared.
What does work: a step-by-step guide
If you don’t like the idea of Google claiming over 4GB of disk space, here are the steps, in order of complexity, to remedy the issue. (Google’s statement does say that “the model will automatically uninstall if the device is low on resources,” without providing more details.)
Step 1. See if you have the toggle
Start by looking for the toggle in Chrome by clicking Settings > System or typing “chrome://settings/system” into the address bar. If you see “On-device AI,” simply toggle it off and restart Chrome. (Step 3 shows how to confirm that it worked.)
If you don’t have the feature, check that Chrome is up to date. Go to Settings > About Chrome, or type “chrome://settings/help.” If the page says that “Chrome is up to date,” you’ve done all you can. Chrome will likely be on an iteration of Version 148, such as “148.0.7778.97 (Official Build).”
Step 2. Back up your computer
From here onward, you will be digging into your operating system, where a wrong step could cause things to break. First, make a full-system backup with software such as Apple’s Time Machine.
Step 3. Look for Gemini Nano on your disk
Whether or not you have the AI toggle in Chrome, you should look to see if the files are on your disk.
On Macs, open a Finder window by clicking Cmd + N from the desktop, and press Cmd + Shift + . (the period character) to reveal hidden system files. Then navigate to Users > [your user name] > Library > Application Support > Google. Right-click the “Chrome” folder, select “Make Alias,” and drag the alias to your desktop so you can get back to it quickly later. Then click the original “Chrome” folder to see what’s inside.
On PCs, in File Explorer, go to Local Disk > This PC > [your user name] > AppData > Google > Chrome. Right-click “Chrome” and select Show more options > Create shortcut, and drag the shortcut to the desktop. Then click Chrome > User Data.
On either system, look for a folder called OptGuideOnDeviceModel. Double-clicking will probably bring you to a folder with a number such as “2025.8.8.1141.” Inside that, you will find several files, including weights.bin—the 4GB+ AI model that makes up most of the package.
Step 4. Assess the situation
If the OptGuideOnDeviceModel folder is not present or is empty, it may be because you do have the toggle in Chrome, and it’s working. Or your system is simply too old to run Gemini Nano. But click that desktop shortcut periodically to see if anything changes.
If Gemini Nano is there, and you aren’t comfortable digging into your macOS or Windows innards, consider other options: Delete Chrome if removing Gemini Nano is more important to you than using the browser, or just live with Gemini Nano if it’s not. Eventually, you should get the toggle to remove the AI model.
If you are willing to tinker, I’ll walk you through the process for macOS, where there may be more need based on my informal polling, and where I was able to thoroughly test. It’s also simpler.
Step 5. Force Chrome to stop re-downloading Gemini Nano
If Chrome doesn’t yet give you the option to remove the model, you’ll have to manually delete it, then set macOS to stop Chrome from downloading Gemini Nano again. This requires copying and pasting a single line of instructions into the back end of macOS.
Quit Chrome, then launch the Terminal app by clicking Applications > Utilities > Terminal. You’ll see a black screen with plain white text (or possibly the inverse). The last line will include your username and a prompt. Mine looks like “seancaptain@Seans-Air ~ %.”
Copy this exact line, paste it into Terminal, and press Return:
defaults write com.google.Chrome GenAILocalFoundationalModelSettings -int 1
That “-int 1” part basically says “Don’t install Gemini Nano.”
This might look scary, but if you type something wrong, Terminal will likely just reject it and give you an error message. If it works, Terminal won’t show anything. No news is good news
Caution: Theoretically, you could restore Gemini Nano by entering a slightly different command (defaults delete com.google.Chrome GenAILocalFoundationalModelSettings). However, that did not bring it back for me in multiple tests, on multiple systems, over several hours. So Gemini Nano may be gone indefinitely if you take this step. (Or restore from backup if you feel remorse.)
Step 6. Delete Gemini Nano
Click your desktop shortcut to the Chrome folder, then drag the OptGuideOnDeviceModel folder into the Trash and empty the Trash. But leave the Chrome folder open so you can keep an eye on it.
Step 7. See if it worked
Launch the Chrome app. Then click your desktop shortcut to the Chrome folder and watch to see if the OptGuideOnDeviceModel appears. If it’s still absent after an hour or so of using Chrome, the process works. If it does reappear, repeat Steps 3 and 4.
This process should eventually stick. But as it goes beyond regular consumer tech operations, there may be quirks to your system that only a pro or sophisticated user could diagnose. Fortunately, you made that system backup, right?
Why should we have to do this?
Google’s quiet bundling of Gemini Nano and slow rollout of ways to get rid of it seem to have hit a nerve. Tech, especially AI, is moving faster than most anyone can hope to keep up with. Emotions run from fear (Will I lose my job? Are they spying on me?) to extreme annoyance (What are all these damn pop-ups offering to think for me?). These latest anxieties come atop years of mistrust based on tech companies gathering data they said they didn’t, using it in ways they said they wouldn’t, and losing it to hackers in ways they said they couldn’t. All that frustration landed with a whopping 4GB thud this week.
Hanff was not a dispassionate reporter of this phenomenon. “You reached in to my device, changed a configuration (the Chrome profile flags), and gave yourself permission to install something I did not authorize,” he wrote in a follow-up post on May 7. (I exchanged some emails with Hanff on technical aspects of the Gemini Nano install and removal.) Both of his posts cite laws that he believes Google has violated by doing this, including the European ePrivacy Directive, the EU and UK General Data Protection Regulations, the California Consumer Privacy Act, and Chapter 9 of the Maltese Criminal Code. Hanff also makes a strident ecological argument, calculating a cost in extra CO2 emissions of pushing out the software ranging from 6,000 to 60,000 metric tons (tonnes). I haven’t checked his math, but he publishes a detailed methodology.
There may be a long debate on the harms or benefits of the mass Gemini Nano deployment. But the scale in itself is noteworthy. A giant company, with a giant user base, put out a giant upgrade with relatively tiny explanation and, until recently, no way to undo it. It may be called “Nano,” but this download is causing big headaches.
