YabZen is a free, open-source browser built on Firefox that brings Arc’s layout, tabs down the side with spaces, folders and Split View, to Mac, Windows and Linux.
Opera One is Opera’s free Chromium browser on every desktop and phone, with a free browser VPN, an ad blocker, messengers in the sidebar and Opera AI. Its agents are in a separate browser, Opera Neon.
The short answer
- if you want Arc’s layout, free and open source
- if you prefer Firefox’s engine and its add-ons
- if you want no AI in your browser at all
- if you want a free browser VPN and an ad blocker built in
- if you keep WhatsApp, Telegram or Slack open in a sidebar
- if you sort work into workspaces, Tab Islands and split screen
- 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
Zen and Opera, with Yab beside them for a Mac.
| What | Zen Browser | Opera | Yab |
|---|---|---|---|
| Made by | Zen Browser team (open-source community project) | Opera | Serafim Korablev |
| Status | Updated | Updated | Updated |
| Runs on | Mac, Windows and Linux | Mac, Windows, Linux, iPhone and Android | Mac |
| Phone app | None; Zen says it has no plans for a mobile version | iPhone, iPad and Android; syncs tabs, bookmarks and Speed Dials with an Opera account | Not yet |
| Price | Free and open source | Free, with Opera AI and a browser VPN; VPN Pro is paid | Free; its AI runs on your own Claude or ChatGPT plan |
| AI | No AI | Chat about pages, on its own AI service | An agent that works in pages, on your Claude or ChatGPT plan |
| Driven by outside agents | No | MCP | MCP and a command line |
| Engine | Gecko | Chromium | WebKit |
| Tabs down the side | Yes | A setting | Yes |
| Spaces | Yes | Yes | Yes |
| Split View | Yes | Yes | Yes |
| Extensions | Firefox add-ons | Chrome Web Store | Chrome Web Store |
| Ad blocker | No | Built in | Built in |
| Open source | Yes | No | 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.
AIOpera leads
Opera has AI built in; Zen has less of it. Zen has no AI: Firefox’s AI features are switched off by default. Opera AI answers about the page, Tab Islands, videos and files, and makes images, with no account; it doesn’t click or fill forms.
Agents like Claude Code and CodexOpera leads
Zen has no MCP server or command line for outside agents. Opera can be driven over MCP, through Browser Connector, in early testing, which lets ChatGPT or Claude read and open tabs but not click or type.
Tabs and windowsZen leads
Zen has tabs down the side, spaces, Split View, folders in the sidebar and tabs that sleep. Opera has tabs down the side as a setting, spaces, Split View, folders in the sidebar and tabs that sleep.
PriceOpera leads
Zen: Free and open source. Opera: Free, with Opera AI and a browser VPN; VPN Pro is paid.
Where it runsOpera leads
Zen runs on Mac, Windows and Linux. Opera runs on Mac, Windows, Linux, iPhone and Android. On a Mac, Zen needs macOS 10.15 or later. Zen has no phone app: Zen says it has no plans for a mobile version. On the phone, Opera: iPhone, iPad and Android; syncs tabs, bookmarks and Speed Dials with an Opera account.
Engine and extensionsa matter of taste
Zen is built on Gecko, Firefox’s engine; Opera on Chromium, as Chrome is. Zen takes extensions from Firefox’s add-ons, Opera from the Chrome Web Store.
PrivacyOpera leads
Zen has open code. Zen sends no telemetry or crash reports, by its privacy policy; optional sync keeps encrypted data on Mozilla’s servers. Opera has an ad blocker built in and a VPN. Opera AI sends only the current page or Tab Island when you write with page access on; Opera says it doesn’t send your history.
What their pages don’t lead with
Real limits, from the makers’ own words and our own use.
Zen Browser
- Releases are still labeled beta
- No phone app, and none planned
- Firefox add-ons only, not the Chrome Web Store
- No ad blocker of its own beyond Firefox’s tracking protection
Opera
- Opera AI only chats and sums up; agents need Opera Neon at $19.90 a month
- The free VPN covers the browser only, with three locations
- The ad blocker is off until you turn it on
- Browser Connector is in early testing and needs an Opera account
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 5, 2026Zen: Spaces, folders and tabs sync between devices with a Mozilla account (1.22b)
- July 23, 2026Opera: Vertical tabs shipped to all Opera One users
- April 16, 2026Opera: Browser Connector lets ChatGPT and Claude read your tabs over MCP (Early Bird)
- February 28, 2026Zen: Live folders for GitHub issues, pull requests and RSS (1.19b)
- December 11, 2025Opera: Opera AI replaced Aria in Opera One, GX and Air
- August 27, 2025Zen: Tab folders added (1.15b)
Questions
Is Zen Browser free?
Yes. Free and open source.
Is Opera free?
Yes. Free, with Opera AI and a browser VPN; VPN Pro is paid.
Which has an AI agent, Zen or Opera?
Neither has an agent that does tasks in your pages. Zen has no AI: Firefox’s AI features are switched off by default. Opera AI answers about the page, Tab Islands, videos and files, and makes images, with no account; it doesn’t click or fill forms.
Do Zen and Opera run on Windows?
Yes, both. Zen runs on Mac, Windows and Linux; Opera on Mac, Windows, Linux, iPhone and Android.
Do Zen and Opera have phone apps?
Opera does. Zen has no phone app: Zen says it has no plans for a mobile version. On the phone, Opera: iPhone, iPad and Android; syncs tabs, bookmarks and Speed Dials with an Opera account.
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 Zen; an agent that works in your signed-in tabs, 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
- Zen home page
- Zen download page (macOS universal, Windows, Linux; beta)
- Zen 1.23.2b release (macOS universal dmg; Info.plist minimum 10.15)
- Zen 1.23.1b release (Firefox 157.0.1)
- Zen license (MPL-2.0)
- Zen AI preferences (all off)
- Zen welcome flow (Firefox import wizard)
- Firefox import from another browser
- Zen 1.15b release (folders)
- Zen 1.19b release (live folders)
- Zen 1.22b release (sync)
- Zen 1.12.9b release (tab unloader uses Firefox tab discarding)
- Zen FAQ (no mobile plans, donations)
- Zen Workspaces
- Zen Split View
- Zen Extensions (addons.mozilla.org)
- Zen Privacy and Security (Firefox password manager, tracking protection)
- Zen privacy policy
- Firefox 157 system requirements
- Opera blog: Opera AI comes to Opera One, GX and Air
- Opera AI feature page
- Opera blog: Browser Connector
- Opera press: Browser Connector (2026-04-16)
- Opera blog: Opera 133 stable, vertical tabs (2026-07-23)
- Opera blog: how vertical tabs work
- Opera blog: Opera One R3
- Opera blog: new native ad blocker (2026-05-14)
- Opera free VPN page
- Opera Workspaces page (split screen, messengers)
- Opera Help: features (tab snoozing, messengers, workspaces)
- Opera Help: security and privacy (ad blocker, VPN)
- Opera Help: Password Manager
- Opera Help: import browsing data
- Opera Help FAQ: Chrome Web Store extensions
- Opera system requirements
- Opera Neon subscription
- Opera blog: Neon free plan for outside agents (2026-08-14)
- Opera blog: Opera One for iOS brings full synchronization (Jul 9, 2026)
- Opera: Sync your Opera browsers
- Opera: Flow / My Flow
- Opera Help (iOS): Connect your computer and phone with Flow
- Opera Browser with VPN on the App Store (iPhone and iPad)
- Opera: Private Web Browser on Google Play
- 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.