Nearly three weeks ago, Mozilla released Firefox 141, an update that introduced several new features. Alongside memory optimizations for Linux systems and a built-in unit converter, the standout addition was AI-powered tab grouping.
This feature uses a local artificial intelligence model to automatically detect related browser tabs, group them together, and suggest descriptive names. Users can also expand these groups with a “Suggest more tabs for group” button, allowing the AI to recommend additional relevant pages.
Mozilla presented the tool as a productivity upgrade, but its reception has been mixed, with performance complaints quickly surfacing.
Users Report Heavy Resource Usage
Multiple posts on the Firefox subreddit describe high CPU usage and reduced battery life linked to the AI grouping feature.
In one case, a user noticed their device heating up and running slowly. A quick check in the system’s task manager revealed a process labeled “Inference”, which is believed to handle Firefox’s on-device AI tasks. Another user using the Conky system monitor reported similar findings, adding that terminating the process caused the browser to crash and require a restart.
These experiences have led to criticism of Mozilla’s decision to include AI in the browser, with some users arguing it bloats the software and strays from its core function of loading and rendering web pages.
AI in Browsers: An Industry Trend
The timing of the backlash reflects the broader technology landscape. Nearly three years after the launch of ChatGPT, AI has become a central focus for tech companies. Microsoft, for instance, has tightly integrated Copilot into its Edge browser, offering features like webpage summarization, text rewriting, and AI-generated images.
Compared to Chrome’s experimental Tab Organizer—which processes data on Google’s servers—Firefox’s approach is more privacy-oriented, running entirely on the user’s device. However, even with local processing, the increased resource demands are proving problematic for some users.
How Firefox’s Tab Grouping AI Works
The system operates through a two-step local process:
- Grouping Tabs – An embedding model analyzes each tab’s title and converts it into a numerical vector. Clustering algorithms then identify patterns to find related pages.
- Naming Groups – The grouped tab data is sent to Mozilla’s smart-tab-topic model, which is based on Google’s T5 architecture. This model suggests a fitting name for each group.
This design ensures that no browsing data leaves the device, but the computational load can still be significant—especially for users with many tabs open at once.
Efficiency Concerns: ONNX vs. GGUF
Some in the community have speculated that Firefox’s choice of model format may be contributing to performance issues. The browser currently uses Microsoft’s Open Neural Network Exchange (ONNX) format for its AI features. Critics suggest that GGUF, an alternative developed by Georgi Gerganov, might run more efficiently on local hardware. Switching formats, however, would require Mozilla to re-engineer parts of the implementation.
Divided User Reactions
The AI grouping tool has generated a split reaction:
- Supporters view it as a time-saver for managing large numbers of tabs, especially during research-heavy tasks.
- Skeptics see it as unnecessary automation that consumes system resources for a task they would rather handle themselves.
This divide reflects a broader hesitation toward AI in consumer software. Some companies, like Zed Industries, have responded by giving users the ability to disable all AI features globally—an option Firefox currently lacks.
Disabling the AI Features in Firefox
While there is no single “turn off AI” button in Firefox, users can disable these features via the browser’s advanced configuration settings:
- Type about:config into the Firefox address bar and accept the warning.
- Use the search bar to locate and set:
browser.ml.chat.enabled→ false (disables the AI chatbot)browser.tabs.groups.smart.enabled→ false (disables AI tab grouping)
The AI chatbot can also be hidden from the sidebar through Settings or Firefox Labs, though some users report it reappears after updates.
