Firefox Smart Window Fills Web Forms and Watches Pages

Firefox Smart Window can now complete online forms using information from browser tabs you select, and it can watch web pages for changes you define. Mozilla announced the update on October 27, 2026, for the opt-in Smart Window beta on desktop. The feature works in English for users in the United States and Canada. It saves retyping, but it also sends the content of the tabs you pick to an AI model, which makes source selection a privacy decision as much as a convenience.

How Firefox Smart Window fills forms

The form tool activates on pages with at least four text fields. When you click into such a form, a "Fill from sources" option appears with a recommended source page. You can add, remove or swap tabs before generating suggestions, then review and edit each proposed answer. Smart Window does not submit forms, so the final click stays with you. Mozilla points to a professional profile or an online portfolio as typical sources, which lets the tool draft answers to job application questions from material you already have open.

Saved autofill data such as names, addresses and phone numbers is handled without AI models, according to Mozilla. The AI layer applies only to the context-driven answers drawn from open tabs. The split matters because the basic autofill you already use stays outside the AI path, while the new option depends entirely on the pages you choose.

What leaves your browser

Mozilla states that information from the selected source pages is shared with Gemini 3.1 Flash Lite, the model that detects form fields and extracts relevant details. Any tab you include, whether it holds employment history, contact details or account pages, is processed by that Google model. Selecting a tab is therefore a decision about which data goes to the model for that task. A banking dashboard or medical portal left selected next to a job application would be included in the same request.

The practical rule is to select only the tabs that hold the information the form needs and to deselect everything else before generating suggestions. Since the tool reads whatever tabs are chosen, the selection step is also where a mistake is easiest to make.

Page monitoring with /watch

The second feature is page monitoring. In the Smart Window chat, typing /watch starts a task in which you describe the change to track and add the pages to check. The Firefox 159.0 release notes give price drops and restocks as examples and say Firefox sends a desktop notification when it finds a match. Matches appear behind the Tasks button in the toolbar, and tasks can also be managed on the about:smartwindowtasks page.

Checks can be scheduled daily or weekly, each task covers up to five pages, and checks run only while Firefox is open. For a shopper waiting on a sale, a closed browser means a missed alert. The feature therefore depends on the browser staying open, not on a background service.

Limits and availability

Form filling currently supports text fields only. Mozilla has indicated that dropdown menus and PDF forms are the next areas of work. Both features run in the desktop Smart Window beta, which users must opt into. The sources do not state any pricing for the beta, and the rollout covers English-language users in the United States and Canada only.

Why this matters

Form filling and page monitoring turn open tabs into working data for Firefox, trading manual retyping for a decision about what the AI is allowed to read. Users who try the feature should treat tab selection as a privacy setting, choose only the pages a task requires, and check every suggestion before submitting.

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Researched and cross-referenced against primary sources by the Bytevyte editorial team. This article was generated with the assistance of artificial intelligence and reviewed by the Bytevyte editorial team.