Mozilla updated Smart Window, Firefox's AI-powered browsing mode, on October 27, 2026 with two agent-style features: AI form filling drawn from your open tabs, and /watch tasks that monitor web pages for changes. Both are rolling out to the Smart Window beta on desktop in the US and Canada. This post covers how they work, the data-sharing detail that matters most, and what to check before turning them on. Our details come from The Verge's report, which cites Mozilla; we could not open Mozilla's own announcement text, so treat quoted behavior as the Verge's account of it.
Quick reference
| Question | Answer |
|---|---|
| New feature 1 | Fill from sources: drafts form text from tabs you select |
| New feature 2 | /watch tasks: monitor pages for sales, job listings and other updates |
| Availability | Smart Window beta, desktop, US and Canada; other countries in coming months |
| Model for form filling | Google Gemini 3.1 Flash Lite, per The Verge |
| Form limits | Text fields only, forms with at least four text fields; dropdowns and PDFs planned |
| Watch limits | Checks daily or weekly, only while Firefox is open; pauses at 60 days without change, stops at 90 |
Fill from sources
Mozilla's example, as relayed by the Verge: pull information from your online portfolio or LinkedIn page to paste your work history into a job application. To use it, click into a form with at least four text fields and choose "Fill from sources". Firefox lists the tabs it will draw from; you select or deselect tabs, and the browser generates suggestions based on them.
This is a narrow, user-directed use of an AI model: you choose the sources and you see suggestions rather than an agent submitting a form. That is a safer design than browser agents that click and submit on their own, a risk we discussed in our look at AI agent privacy promises.
The data-sharing detail
The Verge reports that Mozilla notes data from your source pages is shared with Google's Gemini 3.1 Flash Lite, the model that generates the suggestions. In other words, the text of the tabs you pick leaves your machine and goes to a third-party model provider. If a selected tab is a CV, that is low risk for many people; if it is a bank portal or a health record, it is not.
Earlier hands-on coverage of Smart Window in a Firefox 149 beta, from OMG! Ubuntu, listed three built-in model choices (Google's Gemini Flash Lite, Alibaba Cloud's Qwen3-235B-A22B and OpenAI's GPT-OSS 120B) plus a bring-your-own-model option. Whether form filling lets you choose among those, or always uses Gemini 3.1 Flash Lite, is not clear from the reporting we could read. Check the settings under AI Controls before relying on a specific provider.
Practical rule: only select tabs you would be comfortable pasting into a chatbot, and deselect everything else in the source list.
/watch tasks
Type /watch in the Smart Window chat, describe what you are waiting for, and add the pages to watch. Firefox then checks daily or weekly, but only while the browser is open. When it detects the change, it notifies you via the Tasks button on the toolbar or a desktop notification, if enabled. It pauses if nothing changes for 60 days and stops after 90.
The "only while the browser is open" limit is important. This is not a server-side price tracker. If you close Firefox for a weekend, nothing is checked. For limited-stock drops, a dedicated alert service is still faster; for slow-moving things like a job board or a price that changes weekly, it is convenient. For a deeper look at what such agents can do and where they fail, see our guide to proactive agents from OpenAI, Meta, Anthropic and xAI.
Why Mozilla is doing this
Mozilla's strategy, as OMG! Ubuntu put it in March, is to make AI the primary interface for browsing, with Smart Window as the centerpiece. Today's additions move that from answering questions about pages to acting on your behalf: filling and watching. The trade-off is the usual one for AI features in browsers: usefulness grows with how much of your browsing the model can see, and so does the privacy exposure.
Mozilla's pitch has leaned on choice and control, including multiple built-in model options and a bring-your-own-model setting, per the March hands-on. It is also notable that the shipped model for this feature is a Google model, which will be a talking point for users who chose Firefox to stay away from Google services. Neither the Verge piece nor our sources describe retention terms for source-page data, so we cannot say how long it is kept.
Where Smart Window started
OMG! Ubuntu's March 2026 hands-on, on a Firefox 149 beta build, is useful for seeing how far the feature has come. Smart Window was an optional mode that you turned on with a button in the window frame, and that changed the browser's color scheme. The new tab page dropped the search bar and recommended stories in favor of a prompt box inviting you to ask, search or type a URL. Most pointed questions started a Google search, after which the AI moved to a sidebar, read the top results and produced an answer; if it needed more, it ran follow-up searches on its own.
That first version was an assistant that talked about pages. The reviewer's verdict was mixed: answers were mostly rephrased search results padded with confident inferences, and a memory feature gave them pause. The same piece noted that the beta at that stage could not interact with websites directly: no form filling, no clicking. The October 27 update is the first step across that line, in a limited form.
Try it: three realistic uses
- Job applications. Open your portfolio and LinkedIn in tabs, open the application form, and use Fill from sources with only those two tabs selected. Review each field; the model drafts text, it does not know which version of your history you want to show.
- Price or stock watching. Use
/watchwith a product page and a clear condition such as "notify me if the price drops below a number". Keep Firefox open, and expect daily or weekly checks rather than instant alerts. - Job boards. Watch a company careers page for new listings. Because checks pause after 60 days without a change and stop at 90, re-create the task if you still care after three months.
How this differs from classic autofill
Traditional browser autofill stores a fixed set of fields, such as name, address and card number, and fills them locally by matching field names. Fill from sources is different in kind: it reads free-form content from tabs, uses a language model to interpret it, and writes new text, such as a summary of a job history, into fields that autofill could never handle. That flexibility is the point, and it is also why the data leaves the device while ordinary autofill does not.
It also means errors look different. Classic autofill fails by leaving a field empty or choosing the wrong stored address. A language model can fail by producing fluent text that is slightly wrong: a title you never held, a date that is off by a year. Treat every suggestion as a draft that you are responsible for, especially on applications, tax or government forms.
Open questions
- What retention and training terms apply to the source-page data that goes to Gemini 3.1 Flash Lite?
- Can users pick a different model, including a local one, for Fill from sources?
- Will watch tasks ever run while the browser is closed, for example through a sync service?
- How will Mozilla extend form filling to dropdowns and PDFs without increasing the data sent?
- When will the European release arrive, and will it differ because of regional data rules?
We will update this post if Mozilla publishes more detail.
What to check before you enable it
- Which tabs are selected. The source list is explicit; review it each time.
- Which model is active. Look in Firefox's AI settings for the model choice and any provider terms.
- Retention and training. Read the data-handling note for the model provider; we could not confirm it.
- Form types. Only text fields on forms with four or more fields are supported today.
- Region. The beta is US and Canada only for now.
- Verify the output. Autofilled job histories can contain errors; read before submitting.
How it compares
AI browsers from other vendors lean toward full agents that click through sites. Smart Window's form filling and watch tasks are deliberately smaller steps. That makes them easier to audit but less powerful. If you want the full-agent end of the spectrum, our post on Microsoft's hybrid local and cloud agents for Windows shows where the OS vendors are heading.
Related reading
- AI agent privacy promises: Meta Muse, OpenAI Dots
- Proactive agents compared: Claude Duet, OpenAI Dots, Meta Muse, Grok Bot
- Microsoft hybrid local and cloud agents on Windows
- Brave Leo end-to-end encrypted AI chat
- OpenAI Dots cloud computer and CA certificate claims
- A local AI diary with Hermes Agent
Details are accurate as of October 27, 2026 and based on The Verge's report of Mozilla's announcement.