YabComet vs Firefox
Comet is Perplexity’s free Chromium browser for Mac, Windows, iPhone and Android, with Perplexity’s search and an assistant that can act on pages for you.
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 use Perplexity and want its search and agent in the browser
- if you want one AI browser on Mac, Windows, iPhone and Android
- if you want a free Chromium browser with an ad blocker built in
- 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 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
Comet and Firefox, with Yab beside them for a Mac.
| What | Perplexity Comet | Firefox | Yab |
|---|---|---|---|
| Made by | Perplexity | Mozilla | Serafim Korablev |
| Status | Updated | Updated | Updated |
| Runs on | Mac, Windows, iPhone and Android | Mac, Windows, Linux, iPhone and Android | Mac |
| Phone app | iPhone, iPad and Android; on iPhone it syncs bookmarks and history with desktop Comet | iPhone, iPad and Android; syncs tabs, bookmarks, passwords and history | Not yet |
| Price | Free; Comet Plus $5/month; Perplexity Pro $20/month or Max $200/month for more AI and agent use | 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 service | 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 | No | MCP | MCP and a command line |
| Engine | Chromium | Gecko | WebKit |
| Tabs down the side | Not stated | A setting | Yes |
| Spaces | Not stated | 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.
AIComet leads
Only Comet has an agent that clicks, types and finishes tasks in your pages. Comet’s assistant answers about pages and open tabs and can click, fill forms and navigate for you, asking before it acts. 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 CodexFirefox leads
Comet has no MCP server or command line for outside agents. Firefox can be driven over MCP, through Mozilla’s Firefox DevTools MCP, which starts its own Firefox.
Tabs and windowsFirefox leads
Comet has 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
Comet: Free; Comet Plus $5/month; Perplexity Pro $20/month or Max $200/month for more AI and agent use. Firefox: Free; its built-in VPN is free up to 50 GB a month.
Where it runsFirefox leads
Comet runs on Mac, Windows, iPhone and Android. Firefox runs on Mac, Windows, Linux, iPhone and Android. On a Mac, Comet needs macOS 13 or later and Firefox needs macOS 10.15 or later. On the phone, Comet: iPhone, iPad and Android; on iPhone it syncs bookmarks and history with desktop Comet. On the phone, Firefox: iPhone, iPad and Android; syncs tabs, bookmarks, passwords and history.
Engine and extensionsa matter of taste
Comet is built on Chromium, as Chrome is; Firefox on Gecko, Firefox’s engine. Comet takes extensions from the Chrome Web Store, Firefox from Firefox’s add-ons.
PrivacyFirefox leads
Comet has an ad blocker built in. Comet keeps history, cookies and passwords on your device unless you sync; the assistant sends the page it needs to Perplexity, kept up to 30 days. 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.
Perplexity Comet
- Free use of the assistant is limited; more agent use is Pro at $20 or Max at $200
- No MCP server or command line from Perplexity for coding agents
- Researchers showed prompt-injection attacks on its agent in 2025 (CometJacking)
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 16, 2026Firefox: Smart Window beta expanded from the US and Canada to France
- August 4, 2026Comet: Ninth Circuit vacated the injunction Amazon won against Comet’s shopping agent
- March 24, 2026Firefox: Firefox 149 added split view and a free built-in VPN
- March 18, 2026Comet: Comet for iPhone released
- February 24, 2026Firefox: Firefox 148 added AI Controls with a switch that blocks all AI features
- October 2, 2025Comet: Browser made free for everyone worldwide
Questions
Is Perplexity Comet free?
Yes, with limits on its AI. Free; Comet Plus $5/month; Perplexity Pro $20/month or Max $200/month for more AI and agent use.
Is Firefox free?
Yes. Free; its built-in VPN is free up to 50 GB a month.
Which has an AI agent, Comet or Firefox?
Comet. Comet’s assistant answers about pages and open tabs and can click, fill forms and navigate for you, asking before it acts. 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 Comet and Firefox run on Windows?
Yes, both. Comet runs on Mac, Windows, iPhone and Android; Firefox on Mac, Windows, Linux, iPhone and Android.
Do Comet and Firefox have phone apps?
Both do. On the phone, Comet: iPhone, iPad and Android; on iPhone it syncs bookmarks and history with desktop Comet. On the phone, Firefox: iPhone, iPad and Android; syncs tabs, bookmarks, passwords and history.
Is there a third option on a Mac?
Yab, Yet Another Browser, is free for the Mac: tabs down the side as in Arc, with spaces, folders and Split View; an agent in your signed-in tabs like Comet’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
- Comet help: Operating System Requirements
- Comet help: What is Comet’s browser engine?
- Comet help: Browser features (split view, ad block, extensions, profiles)
- Comet help: Import data
- Comet help: Key settings (memory saver, tab groups)
- Comet help: Built-in password manager
- Comet help: Local data and device storage
- Comet help: Assistant privacy and data use
- Comet Quick Start Guide (Chrome import)
- Comet Assistant vs Agent
- Perplexity changelog Nov 14, 2025 (assistant asks approval before acting)
- Perplexity blog: Introducing Comet Plus ($5)
- Perplexity help: Perplexity Max
- Perplexity help: Local and remote MCPs
- App Store listing (iOS 18+, Pro $20, Max $200)
- TechCrunch: Comet now free (Oct 2, 2025)
- TechCrunch: Comet on Android (Nov 20, 2025)
- MacRumors: Comet on iPhone (Mar 18, 2026)
- Jones Day: Ninth Circuit vacates injunction (Aug 4, 2026)
- LayerX: CometJacking
- Community comet-mcp (not by Perplexity)
- Google Play: Comet: AI Browser & Assistant (updated Sep 24, 2026)
- Comet Help Center: Sync Between Devices
- Perplexity changelog: Comet iOS launch, pair mobile and desktop with device sync (Mar 27, 2026)
- Perplexity blog: Comet is now available on iOS
- Perplexity blog: Comet for Android is here
- MacStories: Comet for iOS review (sync chain, iPad version)
- 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.