If you use AI, Firefox is the browser to beat right now – here’s why

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ZDNET key takeaways

• Mozilla has released Smart Window beta.
• This AI tool is powerful, flexible, and free.
• You can test it on MacOS and Windows.

For most of the past decade, Firefox has been given the short shrift within the world of browsers. However, in the last couple of years, the browser has started to win back the favor it once had. Although I’ve been on and off again with Firefox, I’m starting to lean back towards ‘on,’ thanks to some new additions (such as vertical tabs).

I also just realized that the beta version of Firefox (sadly, only on MacOS and Windows so far) has finally added the free Smart Window feature that Mozilla has been teasing us with for some time. The version of Firefox I’m using is 153 on MacOS Tahoe. I’ve checked Firefox Nightly on Linux, and the feature hasn’t appeared yet. I’ve checked versions 153, Beta, and Nightly (on both Ubuntu and Fedora) and have yet to see the feature (even though I’ve seen others reporting that it works on Linux). To that end, I had to test Smart Window on MacOS.

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Right out of the gate, I’ll say this: if you use AI, do yourself a favor and leave your default browser for Firefox, because you won’t find a smoother, easier option in Microsoft Edge, Chrome, or Safari.

Yeah, Smart Window is that good.

Why is Smart Window better?

At first blush, the best thing about Smart Window is its flexibility. Consider these points:

• You can easily enable or disable the feature.
• You can set it as your default start page if you like.
• You can easily switch between three different models (Fast, Flexible, Personal).
• Smart Window doesn’t slow Firefox down.
• It includes Memories, which are saved pieces of information that help the AI assistant remember things you’ve shared during past conversations.
• You can easily enable/disable Memories on a per-chat basis.

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Given that Smart Window is still in beta, not only is the feature list impressive, but how well it runs has me questioning the beta tag.

Using Smart Window

When you install Firefox 153 or later, or your current instance is upgraded, you’re prompted to select the model you want to use. Instead of Smart Window presenting you with model names, you get three categories:

• Fast – Google gemini-3.1-flash-lite
• Flexible – Alibaba qwen3-235b-a22b-instruct-2507-maas
• Personal – OpenAI gpt-oss-120b

I opted for Flexible as my default, but you can also change the model on a per-chat basis. 

In the next window of the setup wizard, you can choose what Smart Window learns from (Chats in Smart Window and/or browsing across Firefox). After that step, you can set Firefox to always open in Smart Window. That’s it for the wizard. 

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You’ll then be presented with the Firefox browser. If you didn’t set the browser to open automatically to Smart Window, you can open the tool by clicking the Firefox icon near the upper-right corner and selecting Smart Window (beta). 

Smart Window opens to reveal a fairly straightforward chat area where you can begin interacting with the tool. 

Features of Smart Window

You’ll notice a drop-down menu near the bottom-right corner of the chat box. Here you can switch between the three different models on the fly.

At the bottom left of the chat box, there’s a + icon to start a new chat and a tiny computer icon to its right, which is where you can enable or disable the Memories function on a chat-by-chat basis. If you don’t want Smart Window to use collected memories, you can disable it for the current chat. Otherwise, leave the feature enabled.

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Other features found in Smart Window include context-aware assistance (uses open tabs and browsing history to help provide answers and summaries), tab management (helps you group or close multiple tabs based on topics or preferences), search integration (retrieves up-to-date information using your default search engine), and privacy-aware design (operates locally when possible).

Smart Window could tip the scales

I only use AI for research, but when I do, I prefer to use it locally. The downside of that approach is that local AI can sometimes give out-of-date answers or can bring my system to a crawl (especially with more complex research). With Firefox Smart Window, I get the best of both worlds.

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Does that mean this feature could tip the scales and bring me back to Firefox? My answer is simple: if you combine Smart Window with the recent additions to Firefox, plus the usual attention to security, the answer becomes clear.

Yes, I am starting to lean back towards making Firefox my default browser. Currently, the only thing preventing me from doing so is the lack of a Workspaces feature. Thanks to Opera and Vivaldi, I’ve grown to depend on Workspaces to keep my tabs better organized. You can bet that the second Firefox includes Workspaces (and not by way of one of the poorly designed extensions), I’ll be bouncing right back to Mozilla’s browser like Tigger.

Give Firefox’s Smart Window a try and see if it doesn’t lure you back to one of the best open-source web browsers on the market.