How to Remove Gemini Nano Files from Chrome (Reclaim 4GB)

Chrome’s Gemini Nano model is a 3-4GB file named weights.bin, stored in a folder called OptGuideOnDeviceModel inside your Chrome user data directory. Chrome downloaded it silently (widely reported in May 2026). Deleting the file alone does not work: with on-device AI still enabled, Chrome re-fetches the full 3-4GB. To reclaim the space for good, disable the feature first, then the file deletes itself.

Order matters here, and it’s what most “just delete the folder” guides skip. Below is the path that actually frees the disk and keeps it free, on each OS.

Find the File First (Confirm You Have It)

Before changing anything, check whether the model is even on your machine — the rollout was gradual, so not every profile has it.

Windows. Open File Explorer and paste this into the address bar:

%LOCALAPPDATA%\Google\Chrome\User Data\OptGuideOnDeviceModel

If a weights.bin file is sitting there, the download happened. Right-click it → Properties to see the exact size (typically 3-4GB).

macOS. In Finder, press Cmd+Shift+G and go to:

~/Library/Application Support/Google/Chrome/OptGuideOnDeviceModel

Linux. The folder lives under your Chrome config directory:

~/.config/google-chrome/OptGuideOnDeviceModel

If the folder is absent or empty, your profile has not received the model, and there is nothing to reclaim. If it is there, continue — but do not delete it yet. Deleting now, before the next step, wastes the effort.

Why Deleting the File Alone Fails

Chrome’s optimization-guide system treats the on-device model as something it is responsible for keeping present. When the feature that uses it is enabled, Chrome periodically checks that the model exists and is current. Find it missing, and Chrome re-downloads the entire 3-4GB on the next eligible window — usually within a browsing session or two.

So the hand-delete approach gives you the disk space back for an hour, then quietly takes it again, often over metered or slow connections you did not choose to spend on a 4GB transfer. People who only delete the folder end up doing it repeatedly and assuming the file is “stuck.” It is not stuck. The feature behind it is still asking for it.

The reliable sequence is: turn the feature off, which makes Chrome stop wanting the model, then the file is safe to remove (and Chrome removes it for you).

Remove It and Keep It Gone

Three options, easiest to most permanent. For most people, Option 1 is the whole job.

Option 1: Toggle Off On-Device AI (Reclaims Space Instantly)

This is the cleanest path and it deletes the file for you — no manual delete needed.

1. Go to chrome://settings.
2. Click System in the left sidebar.
3. Toggle On-device AI off.
4. The weights.bin file deletes immediately. The 3-4GB comes back with no restart required.

The toggle was added in early 2026 after the silent-download behavior became public. Because it removes the file as part of disabling the feature, you never touch File Explorer. Confirm by revisiting the OptGuideOnDeviceModel folder from the previous section — it should now be empty or gone.

Option 2: Disable the Flag, Then Delete

If your Chrome version does not show the System toggle, use the flag.

1. Open chrome://flags.
2. Search for optimization-guide-on-device-model and set it to Disabled.
3. Search for prompt-api-for-gemini-nano and set it to Disabled too.
4. Click Relaunch.
5. After the restart, delete the OptGuideOnDeviceModel folder by hand from the path in the first section.

With both flags off, Chrome no longer requests the model, so the manual delete sticks. The caveat: flags can reset on major Chrome updates, so re-check after a version bump. If it reset and the folder reappeared, that is why.

Option 3: Set a Policy (Survives Updates)

For a machine where you never want the model back — a small SSD, a metered connection, a locked-down setup — a policy outlasts both the toggle and the flag.

Windows (Registry):

1. Open Registry Editor (regedit).
2. Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome (create the keys if they do not exist).
3. Create a DWORD value named GenAILocalFoundationalModelSettings and set it to 1.
4. Restart Chrome. Confirm at chrome://policy that the value shows under Machine Policies.

macOS (managed preferences):

Place a com.google.Chrome.plist in /Library/Managed Preferences/ with:

<key>GenAILocalFoundationalModelSettings</key>
<integer>1</integer>

A policy survives Chrome updates and profile resets, which flags do not. It also blocks the related on-device AI features from re-activating and pulling the model again.

What You Lose by Removing It

Removing the model is low-cost, and being specific about the cost matters more than a blanket “you won’t notice.”

The model powers two things. The first is on-device scam detection in the address bar — Chrome’s local check that flags some malicious sites without sending data to Google. The second is the Prompt API for Gemini Nano, which a handful of third-party developer tools and extensions call for local AI features. If you do not use those tools, this is invisible.

What you do not lose: your profile, bookmarks, history, saved passwords, extensions, or sync. The weights.bin file is a downloadable model, not user data. Nothing about your Chrome setup depends on it, which is why deleting it is safe in a way that deleting most files in the Chrome data directory is not.

If on-device scam detection is something you want to keep but you still object to the silent 4GB download, that’s a genuine trade-off — the scam check needs the model to run. Most users weighing 4GB of disk against a feature they did not know existed choose the disk back.

After You Reclaim the Space

Clawing back 4GB once is a one-time win. The recurring version of the same instinct — wanting Chrome to use fewer resources without you babysitting it — is a different fix.

SuperchargePerformance suspends idle tabs via chrome.tabs.discard() so background tabs stop holding RAM, and it goes after the heavy ones first: a fast-path drops any tab over 200MB after a few minutes idle instead of waiting on a flat timer, while a protect list of around 30 apps leaves a playing tab, an active form, or your email open. Its 186K+ blocking rules across 22 sources keep ad and tracker scripts (themselves a steady disk-cache and memory drain) from loading in the first place, and cookie-banner auto-reject is on by default. It runs locally, with no account and zero telemetry. Clearing Gemini Nano is a one-time tidy-up. Keeping Chrome light every day is the bit that actually saves you.

If your underlying concern is the AI features themselves rather than the disk, the companion piece — how to disable Chrome’s AI features and Gemini — walks through turning off the Gemini sidebar, page content sharing, and AI Overview, not just the on-device model. And if the 4GB download was part of a broader Chrome disk-usage problem, fixing Chrome’s 100% disk usage on Windows covers the other common causes.