Firefox AI slammed for hogging CPU and draining battery

Mozilla recently rolled out Firefox version 141 with many new features, including AI-powered tab grouping. The browser can now scan your open tabs, figure out which ones are related, and group them with labels.

On paper, it sounds like a dream for anyone juggling dozens of tabs at once. In practice, some users say it is taking a toll on their PC’s CPU. Posts on the Firefox subreddit describe laptops running hot, fans going full blast, and battery life taking a hit.

One Reddit user said the update blew up their CPU after opening multiple tabs. Apparently, a mysterious process called “Inference” in the task manager shows that it is eating up resources until the browser is restarted.

Mozilla’s system keeps everything on your device, which means your browsing data stays private. But it also means the AI has to do all the work locally, and that can be heavy lifting if you have a tab hoarding habit.

A few Firefox fans are pointing the finger at Mozilla’s choice of Microsoft’s ONNX format for the AI models, saying that more lightweight formats might run smoother. Others aren’t bothered at all, arguing it’s a genuinely useful tool for research and big projects.

If you are among those affected and want the feature disabled, here’s what to do. You can head into Firefox’s advanced settings to disable the smart tab grouping. You can even delete the AI models entirely from the add-ons page.

Mozilla says more AI features are coming this year, joining Chrome and Edge in the push to make browsers smarter. Whether that makes Firefox more helpful or more of a battery hog will likely depend on how many tabs you keep open.