Firefox's Smart Window now fills forms from tabs you pick, using Google's Gemini 3.1 Flash Lite

Mozilla announced on October 27, 2026, that Smart Window, the opt-in AI mode in Firefox, can now fill in web forms using information from tabs you choose. A job application that asks for your work history, for example, can be filled from an open portfolio or professional profile. To do that, Firefox shares information from those tabs with Gemini 3.1 Flash Lite, a model made by Google.

How form filling works

The option appears when you click into a form with at least four text fields that Smart Window can help with. A “Fill from sources” entry shows up in the dropdown, together with a recommended source page, and a pencil icon lets you add or remove tabs. Smart Window then proposes values, which you review and can edit before sending. It never submits the form itself.

Firefox's ordinary autofill is unchanged. Saved details such as your name and address still go into forms without any AI model, and those saved values stay on the device. The new feature handles only text fields for now and does not keep the text it generates. Mozilla says it is exploring dropdown menus, PDF forms, and a way to save generated answers for later forms.

What the model gets to see

According to Mozilla, information from the selected source pages is shared with Gemini 3.1 Flash Lite, which detects the form fields and pulls out the relevant details. The model you picked for Smart Window chat stays the same. This suggests that picking source tabs is also a decision about what Google's model receives.

Mozilla's post does not say which version of Qwen handles page watching, where that model runs, or whether the content of watched pages leaves your computer. It also does not say how long information sent for form filling is kept.

Watching pages for a change

The second feature starts when you type /watch in the Smart Window chat. You describe what you are waiting for, such as a price drop or a job listing with a particular title, and add up to five pages to the task. Firefox checks them daily or weekly, but only while the browser is open.

A match appears under the Tasks button in the toolbar, and as a desktop notification if those are turned on. You can keep up to 15 tasks active at once. A task pauses after 60 days without a matching change, and checking stops entirely after 90 days.

For now, both features are limited to the English desktop beta of Smart Window in the United States and Canada. Mozilla says other markets will follow in the coming months.