The Firefox 159 new features arrive with an unusual headline: an AI-assisted tool that can check selected webpages for changes on your behalf. Mozilla calls it Smart Window, and its new /watch command can look for a price drop, an item returning to stock, or a relevant job opening. There is an important qualification, however. Firefox 159 has reached Mozilla’s stable Release channel, but website monitoring is initially a progressive rollout in the desktop beta—not a capability available to every Firefox 159 user.
Released on October 27, Firefox 159 also makes saved passwords easier to reach, improves open-tab search, expands native sharing on macOS, and addresses memory, graphics, networking, import, and file-upload problems. Mobile users receive targeted reliability fixes as well. Here is what has changed, who can use the new monitoring feature, and how to install the Firefox 159 update safely.
Smart Window’s /watch command leads the Firefox 159 release
Smart Window is Mozilla’s experimental AI-focused browsing environment. According to Mozilla’s October 27 Smart Window announcement, the new /watch command lets a user describe a desired change in ordinary language and assign webpages to a monitoring task.
For example, someone shopping for a laptop could ask Firefox to watch a product page for a lower price. A job seeker could monitor several employer career pages for listings containing a particular role, location, or skill. The system can also look for an out-of-stock product becoming available again.
Users can add webpages to a task, choose daily or weekly checks, and receive matching results through the Tasks button on the Firefox toolbar and through desktop notifications. Watches can be reviewed or changed in the Smart Window interface or by visiting about:smartwindowtasks. Mozilla currently permits up to five pages per task and up to 15 active tasks.
What AI website monitoring does—and does not do
The feature is better understood as AI-assisted matching than as a real-time alert service. Mozilla says it uses the Qwen AI model to evaluate selected pages against the instructions supplied for a task. If a user asks for “remote accounting jobs in Ohio,” for example, the model attempts to identify page content that matches that request.
It does not guarantee an instant price notification or immediate stock alert. Checks occur at the selected daily or weekly frequency, and they run only while Firefox is open. A change that happens between checks could be reported later—or potentially disappear before the next check. Time-sensitive shoppers should not treat it as a substitute for a retailer’s own alerts.
Availability is limited, too. Mozilla is progressively rolling out monitoring through the Smart Window desktop beta, initially in English for users in the United States and Canada. That means installing stable Firefox 159 does not ensure that /watch will appear. Mozilla has not said that every country, operating system, or Firefox installation has immediate access.
Privacy and the Qwen model
Because a watch must evaluate selected webpages, users should consider the sensitivity of any page they add. Mozilla identifies Qwen as the model used by the monitoring feature, but that does not mean all Firefox browsing activity is continuously uploaded or watched. The capability operates on the pages deliberately assigned to a task, subject to Mozilla’s implementation and applicable service terms.
A separate privacy-relevant change affects the AI chatbot menu’s Summarize page option. Mozilla’s Firefox 159 release notes say the option now shares the page’s address with the selected chatbot provider instead of sending the page’s text content. That is a precise change to this action; it should not be interpreted as a universal statement about how every chatbot provider handles URLs, prompts, account information, or subsequent interactions.
Firefox 159 new features for passwords, tabs, and shortcuts
Several everyday interface improvements are available beyond the experimental monitoring rollout. The most visible may be direct access to saved passwords from the Firefox sidebar by default. The Firefox password sidebar reduces the need to leave the current browsing context when looking up a saved login.
Firefox 159 also makes open-tab search easier to invoke. Press Ctrl+Shift+A on Windows or Linux, or Cmd+Shift+A on macOS, to search through open tabs. This is particularly helpful for users who keep multiple windows or large tab collections open.
Mozilla has also changed the keyboard shortcuts associated with Extensions and Themes. Users who dislike the defaults can customize them through about:keyboard. Because custom shortcuts can overlap with operating-system commands or other Firefox actions, check for conflicts when assigning a new combination.
macOS gains a more capable native sharing picker
On macOS, Firefox 159 integrates more fully with Apple’s native sharing picker. The interface can include page previews, recent contacts, AirDrop, Messages, and other sharing destinations supported by the Mac.
The notable addition is support for sharing multiple selected tabs in one action. That can be useful when sending a group of travel options, research sources, product comparisons, or project references. As a platform-specific feature, it should not be expected on Windows, Linux, or Android.
Firefox 159 bug fixes users may notice
The Firefox 159 bug fixes cover several narrowly defined situations. Not every user will see a difference, but the update could be significant for people affected by one of the following problems.
Linux memory and Wayland improvements
- AMD graphics and map results: Firefox addresses excessive memory use on Linux computers with AMD graphics when displaying maps or place results on services such as ChatGPT. This targeted Firefox Linux memory fix is most relevant to users with that hardware and workload.
- Minimized web apps: Mozilla has fixed rapid memory growth that could occur when a minimized web application, such as Zoom, remained open. The change may help users who leave communication tools running for long periods.
- Wayland tab detachment: A Linux Wayland issue could cause a tab to detach unexpectedly into a separate window. Firefox 159 corrects that behavior.
Windows video and cross-platform reliability fixes
- NVIDIA RTX Video HDR: Some videos could display incorrectly on Windows systems with NVIDIA RTX Video HDR enabled. The update includes a fix for that configuration.
- Chrome bookmark imports: Firefox corrects failures that could occur when importing bookmarks from Chrome profiles signed in to a Google account.
- HTTP/3 fallback: Sites including Slack could fail to fall back to HTTP/2 when an HTTP/3 request was rejected. The networking correction should improve access under those conditions.
- File uploads: File-selection dialogs could reopen in the wrong folder, creating extra navigation during repeated uploads. Firefox 159 addresses the folder-handling problem.
These fixes should not be read as evidence that every Firefox user had a memory leak, video problem, or networking failure. Hardware, operating system, graphics settings, site behavior, and usage patterns determine whether a particular correction is noticeable.
Firefox for Android receives tab and video fixes
The mobile portion of the release focuses on reliability. Firefox for Android includes improvements for tabs that reload unexpectedly, with particular relevance to some Xiaomi and Redmi devices. Mozilla also lists a correction for video playback failures on certain websites.
Android behavior can vary because phone manufacturers modify memory management, battery optimization, and background-process rules. Users experiencing persistent reloads should install the update and then review device-specific battery restrictions if the problem continues.
Web-platform additions for developers
Firefox 159 expands support for modern web capabilities, although these changes are secondary for most consumers. Scroll-driven CSS animations allow animation progress to respond to scrolling rather than a conventional time-based timeline. Developers can use the feature for effects such as reading indicators and elements that animate as they enter a scrollable area.
The release also adds support associated with scoped custom element registries. These let developers define custom elements within a particular scope, reducing naming conflicts and making independently developed component systems easier to combine. Site owners should still test implementations across their supported browsers before relying on either capability in production.
How to install the Firefox 159 update safely
- Open Firefox and select the application menu button.
- Choose Help, followed by About Firefox.
- Allow Firefox to check for and download an available update.
- Install the offered update and restart the browser if prompted.
On Android or iOS, use the official app store for the device and check the Firefox listing for updates. Managed workplace computers may receive the release later according to an administrator’s deployment schedule.
If a manual installer is necessary, use the official Mozilla Firefox download page. Avoid third-party download portals, repackaged installers, and advertisements designed to resemble update buttons. Consider backing up essential data before any major browser change, especially if the profile contains local bookmarks or settings that are not synchronized.
Should you update to Firefox 159?
For most users, the Firefox 159 release is a sensible maintenance update. People affected by Linux memory growth, Wayland tab detachment, Windows HDR video problems, failed Chrome imports, or Android playback issues have especially clear reasons to install it.
Smart Window’s page monitoring is potentially useful for shoppers, researchers, and job seekers, but expectations should remain realistic. It is a beta feature in a progressive, region-limited rollout; checks require Firefox to remain open; and daily or weekly schedules are not equivalent to real-time tracking. For users who receive access and understand those constraints, /watch could reduce repetitive page checking without pretending to eliminate it completely.
Frequently asked questions
Is Firefox 159 a stable release?
Yes. Mozilla’s official version-specific release notes list Firefox 159 on the stable Release channel beginning October 27. Smart Window monitoring is different: that capability is being progressively introduced through the desktop beta and should not be treated as universally available in stable Firefox.
How do I use Firefox Smart Window to monitor a webpage?
If the rollout has reached your eligible Smart Window installation, use the /watch command, describe the change you want Firefox to identify, and add up to five relevant pages to the task. Choose daily or weekly checks. Results can appear through the Tasks toolbar control and desktop notifications, while active watches can be managed in Smart Window or at about:smartwindowtasks.
Will Firefox notify me immediately when a price drops?
No immediate alert is guaranteed. Monitoring runs according to the selected daily or weekly schedule and only while Firefox is open. The AI attempts to match page changes to the request, but it is not a real-time retailer inventory or pricing feed.
Does Firefox 159 send every webpage to an AI provider?
Mozilla does not describe Smart Window monitoring as continuously uploading all browsing activity. Users select pages for individual watch tasks. Separately, the chatbot Summarize page action now sends the page address rather than the page’s text to the chosen provider. Users should still review the provider’s terms before sharing sensitive URLs or prompts.
Where can I download Firefox 159?
The safest choices are Firefox’s built-in updater, the official mobile app store, or Mozilla’s own download page. Do not install the browser from an unknown software mirror or third-party update prompt.
