YabAside vs Firefox
Aside is an AI agent browser from a Y Combinator startup, on Chromium, for Mac and Windows. Its agent does multi-step work in the sites you are signed in to, on Aside’s own models or your ChatGPT or Claude plan.
Firefox is Mozilla’s open-source browser on its own engine, Gecko, on every desktop and phone. Its AI is optional: a Smart Window beta and a sidebar chatbot, all behind one switch.
The short answer
- if you want an agent for multi-step work across your signed-in sites, on Mac or Windows
- if you want a free plan with AI credits, or to bring your ChatGPT or Claude plan
- if you want Claude Code or Codex to drive it over MCP or its command line
- if you want an open-source browser that isn’t Chromium
- if you want AI off by default, or gone with one switch
- if you want a free browser VPN, where it is offered
- if you miss Arc and want spaces, pins and folders kept, on a Mac
- if you already pay for Claude or ChatGPT and want it to work in your signed-in tabs
- if you want Claude Code, Codex or Cursor to drive a real browser over MCP
At a glance
Aside and Firefox, with Yab beside them for a Mac.
| What | Aside | Firefox | Yab |
|---|---|---|---|
| Made by | Aside Computer Inc. (YC Fall 2025) | Mozilla | Serafim Korablev |
| Status | Updated | Updated | Updated |
| Runs on | Mac and Windows | Mac, Windows, Linux, iPhone and Android | Mac |
| Phone app | None yet; an iPhone app is in the works. Pro runs its agent from Slack or Telegram | iPhone, iPad and Android; syncs tabs, bookmarks, passwords and history | Not yet |
| Price | Free with 500 AI credits a month; Pro $20/month; Max $200/month; or your own ChatGPT or Claude plan | Free; its built-in VPN is free up to 50 GB a month | Free; its AI runs on your own Claude or ChatGPT plan |
| AI | An agent that works in pages, on its own AI or yours | Chat about pages, on its own AI or yours | An agent that works in pages, on your Claude or ChatGPT plan |
| Driven by outside agents | MCP and a command line | MCP | MCP and a command line |
| Engine | Chromium | Gecko | WebKit |
| Tabs down the side | Yes | A setting | Yes |
| Spaces | Yes | No | Yes |
| Split View | Yes | Yes | Yes |
| Extensions | Chrome Web Store | Firefox add-ons | Chrome Web Store |
| Ad blocker | Built in | No | Built in |
| Open source | No | Yes | No |
Checked October 9, 2026 on each maker’s own pages, linked under Sources. Prices are per month, in US dollars.
Where they differ
What separates them, area by area. Where one plainly has more, it says who; where it comes down to taste, it says so.
AIAside leads
Only Aside has an agent that clicks, types and finishes tasks in your pages. Aside’s agent runs multi-step tasks in your signed-in sites, signs in from its own password vault without seeing the passwords, and asks before payments, posts and messages. Firefox’s Smart Window beta chats with tabs you share and groups them, and a sidebar chatbot can use Claude, ChatGPT, Gemini, Le Chat or Copilot; it can’t click or fill forms, and one switch turns all AI off.
Agents like Claude Code and CodexAside leads
Aside can be driven over MCP and a command line, through the aside command line, with aside mcp as its MCP server. Firefox can be driven over MCP, through Mozilla’s Firefox DevTools MCP, which starts its own Firefox.
Tabs and windowsAside leads
Aside has tabs down the side, spaces, Split View, folders in the sidebar and tabs that sleep. Firefox has tabs down the side as a setting, Split View, folders in the sidebar and tabs that sleep.
PriceFirefox leads
Aside: Free with 500 AI credits a month; Pro $20/month; Max $200/month; or your own ChatGPT or Claude plan. Firefox: Free; its built-in VPN is free up to 50 GB a month.
Where it runsFirefox leads
Aside runs on Mac and Windows. Firefox runs on Mac, Windows, Linux, iPhone and Android. On a Mac, Aside needs macOS 15 or later and Firefox needs macOS 10.15 or later. Aside has no phone app yet: an iPhone app is in the works. Pro runs its agent from Slack or Telegram. On the phone, Firefox: iPhone, iPad and Android; syncs tabs, bookmarks, passwords and history.
Engine and extensionsa matter of taste
Aside is built on Chromium, as Chrome is; Firefox on Gecko, Firefox’s engine. Aside takes extensions from the Chrome Web Store, Firefox from Firefox’s add-ons.
PrivacyFirefox leads
Aside has an ad blocker built in. Aside keeps task transcripts and files on your Mac; model providers get the prompts, page snapshots and screenshots a task needs, and analytics sharing is on by default. Firefox has a VPN and open code. Smart Window sends prompts and what you share through Mozilla’s servers to partner models; Mozilla says it keeps no chat logs without permission and doesn’t train on them.
What their pages don’t lead with
Real limits, from the makers’ own words and our own use.
Aside
- The free plan has 500 AI credits a month; more is Pro at $20 or Max at $200
- Mac (macOS 15 or later) and Windows only, no phone apps
- Young: first released in February 2026, on Windows since September 2026
- Agents may use your saved passwords unless you change the default
Firefox
- Its Smart Window AI is a beta in the US, Canada and France and needs a Mozilla account
- Its AI can’t click, fill forms or buy for you
- The free VPN covers the browser only, up to 50 GB a month, in a few countries
- Firefox add-ons only, not the Chrome Web Store
Yab, honestly
- Mac only: macOS 15.4 or later, no Windows, iPhone or Android
- New: first released in September 2026
- Its AI needs a Claude or ChatGPT plan; ChatGPT’s free plan may work with low limits
- WebKit, as in Safari: a site tested only in Chrome can misbehave
- Closed source
What changed lately
- September 21, 2026Aside: Ad blocking with default filter lists turned on during setup
- September 16, 2026Firefox: Smart Window beta expanded from the US and Canada to France
- September 14, 2026Aside: Windows version officially available (release 1.0.914.1)
- March 24, 2026Firefox: Firefox 149 added split view and a free built-in VPN
- February 25, 2026Aside: First Aside Browser release for macOS
- February 24, 2026Firefox: Firefox 148 added AI Controls with a switch that blocks all AI features
Questions
Is Aside free?
Yes, with limits on its AI. Free with 500 AI credits a month; Pro $20/month; Max $200/month; or your own ChatGPT or Claude plan.
Is Firefox free?
Yes. Free; its built-in VPN is free up to 50 GB a month.
Which has an AI agent, Aside or Firefox?
Aside. Aside’s agent runs multi-step tasks in your signed-in sites, signs in from its own password vault without seeing the passwords, and asks before payments, posts and messages. Firefox’s Smart Window beta chats with tabs you share and groups them, and a sidebar chatbot can use Claude, ChatGPT, Gemini, Le Chat or Copilot; it can’t click or fill forms, and one switch turns all AI off.
Do Aside and Firefox run on Windows?
Yes, both. Aside runs on Mac and Windows; Firefox on Mac, Windows, Linux, iPhone and Android.
Do Aside and Firefox have phone apps?
Firefox does. Aside has no phone app yet: an iPhone app is in the works. Pro runs its agent from Slack or Telegram. On the phone, Firefox: iPhone, iPad and Android; syncs tabs, bookmarks, passwords and history.
Can I move from Firefox to Aside?
Yes: Aside’s own help says it brings in from Firefox.
Is there a third option on a Mac?
Yab, Yet Another Browser, is free for the Mac: tabs down the side with spaces, folders and Split View, as in Aside; an agent in your signed-in tabs like Aside’s, on the Claude or ChatGPT plan you already pay for. Claude Code, Codex and any MCP client can drive it too. It runs on WebKit, the engine Safari uses, and takes Chrome extensions. It is Mac only, and new.
More comparisons
- Aside home page
- Aside pricing
- Aside download page (macOS and Windows)
- Aside help: Get started (macOS 15 or later, import)
- Aside help: Manage your subscription
- Aside help: Configure AI providers
- Aside help: CLI, MCP and REPL
- Aside help: Browser basics (split tabs)
- Aside help: Password autofill and AI access policy
- Aside help: Privacy (analytics default on)
- Aside Browser changelog (Chromium, Windows, Memory Saver, imports, Intel fix)
- Aside components changelog (ad blocking, Sept 21 2026)
- Aside privacy policy (June 23 2026)
- Y Combinator company page
- Aside job listing: MTS, Mobile Engineer (iOS), build the iOS app from the ground up
- PiunikaWeb (Jul 20, 2026): Aside team member says a mobile app will ship soon
- Mozilla blog: Smart Window
- Mozilla Support: get started with Smart Window
- Mozilla Support: model choices in Smart Window
- Smart Window privacy notice
- Firefox.com: Smart Window
- Mozilla blog: window types (2026-09-24)
- Mozilla blog: AI on your terms (AI controls)
- Firefox 148 release notes
- Firefox 149 release notes (split view, VPN)
- Mozilla blog: free built-in VPN
- Firefox 136 release notes (vertical tabs)
- Firefox 138 release notes (tab groups)
- Bugzilla 1730066: tab unloading enabled on macOS (Firefox 95)
- Firefox system requirements
- Firefox ESR 115 release notes (import sources)
- Firefox DevTools MCP (Mozilla)
- Firefox.com: Firefox browser sync
- Firefox on the App Store (iPhone and iPad)
- Firefox on Google Play
- Mozilla Support: Sync Firefox data
- Yab Manual: Bringing in from another browser
- Yab Manual: Connecting Claude or ChatGPT
- Yab Manual: Extensions
- Yab Manual: Yab’s tools over MCP
- Yab Manual: Privacy
Yab, Yet Another Browser.
Free for the Mac. Arc’s sidebar, your own Claude or ChatGPT as the agent, Chrome extensions on WebKit.