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.
Arc is The Browser Company’s Chromium browser for Mac and Windows that put tabs down the side, with spaces, folders and Split View. It has had no new features since May 2025; it still gets security fixes, and its makers point people to Dia.
Zen is the closest open-source take on Arc’s layout, built on Firefox instead of Chromium. Arc still works but has had no new features since May 2025; Zen ships often but is still labeled beta. The catch in moving: Zen runs Firefox add-ons, not Chrome extensions.
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 use it today and want its sidebar, spaces and Split View exactly as they are
- if you want a free browser with no paid AI plans
- if you need the same layout on Windows
- 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
At a glance
Zen and Arc, with Yab beside them for a Mac.
| What | Zen Browser | Arc | Yab |
|---|---|---|---|
| Made by | Zen Browser team (open-source community project) | The Browser Company (Atlassian) | Serafim Korablev |
| Status | Updated | Security fixes only | Updated |
| Runs on | Mac, Windows and Linux | Mac and Windows | Mac |
| Phone app | None; Zen says it has no plans for a mobile version | Arc Search on iPhone, iPad and Android; on iPhone it shows your desktop spaces and pins | Not yet |
| Price | Free and open source | Free; its Arc Max AI helpers are free too | 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 | No | MCP and a command line |
| Engine | Gecko | Chromium | WebKit |
| Tabs down the side | Yes | Yes | Yes |
| Spaces | Yes | Yes | Yes |
| Split View | Yes | Yes | Yes |
| Extensions | Firefox add-ons | Chrome Web Store | Chrome Web Store |
| Ad blocker | No | No | 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.
AIArc leads
Arc has AI built in; Zen has less of it. Zen has no AI: Firefox’s AI features are switched off by default. Arc Max helpers tidy tab titles and downloads, preview links and put ChatGPT in the command bar; Ask on Page was removed in August 2025, and there is no agent.
Tabs and windowseven
Both have tabs down the side, spaces, Split View, folders in the sidebar and tabs that sleep.
PriceArc leads
Zen: Free and open source. Arc: Free; its Arc Max AI helpers are free too.
Where it runsZen leads
Zen runs on Mac, Windows and Linux. Arc runs on Mac and Windows. On a Mac, Zen needs macOS 10.15 or later and Arc needs macOS 13 or later. Zen has no phone app: Zen says it has no plans for a mobile version. On the phone, Arc: Arc Search on iPhone, iPad and Android; on iPhone it shows your desktop spaces and pins.
Engine and extensionsa matter of taste
Zen is built on Gecko, Firefox’s engine; Arc on Chromium, as Chrome is. Zen takes extensions from Firefox’s add-ons, Arc from the Chrome Web Store.
PrivacyZen 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. Arc has no ad blocker of its own. Arc needs an account; The Browser Company says it doesn’t see which sites you visit, and Arc Max sends page data to OpenAI and Anthropic.
UpdatesZen leads
Zen is updated as usual. Arc: No new features since May 2025; Chromium security updates still come, the latest on October 8, 2026.
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
Arc
- No new features since May 2025, only security updates
- Needs an Arc account
- No ad blocker of its own
- On phones, Arc Search is a separate search app
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)
- February 28, 2026Zen: Live folders for GitHub issues, pull requests and RSS (1.19b)
- October 21, 2025Arc: Atlassian completed its purchase of The Browser Company
- August 28, 2025Arc: Ask On Page removed from Arc Max
- August 27, 2025Zen: Tab folders added (1.15b)
- May 26, 2025Arc: The Browser Company stopped feature work on Arc to focus on Dia
Questions
Is Zen Browser free?
Yes. Free and open source.
Is Arc free?
Yes. Free; its Arc Max AI helpers are free too.
Which has an AI agent, Zen or Arc?
Neither has an agent that does tasks in your pages. Zen has no AI: Firefox’s AI features are switched off by default. Arc Max helpers tidy tab titles and downloads, preview links and put ChatGPT in the command bar; Ask on Page was removed in August 2025, and there is no agent.
Do Zen and Arc run on Windows?
Yes, both. Zen runs on Mac, Windows and Linux; Arc on Mac and Windows.
Do Zen and Arc have phone apps?
Zen has no phone app: Zen says it has no plans for a mobile version. On the phone, Arc: Arc Search on iPhone, iPad and Android; on iPhone it shows your desktop spaces and pins.
Is Arc still being updated?
No new features since May 2025; Chromium security updates still come, the latest on October 8, 2026.
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
- Arc home page (Chromium updates only, Mac and Windows downloads)
- Letter to Arc members, 2025-05-26
- Arc for macOS release notes
- Arc for Windows release notes
- Arc macOS update feed (minimum macOS 13.0; universal binary)
- Arc unsupported devices
- Arc Max help article
- Arc import help article
- Arc ad blocking and Manifest V3
- Arc saved passwords
- Why Arc needs an account
- Arc Spaces
- Arc Split View
- Arc Folders
- Arc Search for iOS and Android
- Arc Search on the App Store (1.48.0, 2026-08-12)
- Arc Search for Android release notes
- Arc privacy policy
- Atlassian completes acquisition of The Browser Company (Business Wire)
- Arc Help: Arc Sync (what syncs, not on Android)
- Google Play: Arc Search (updated Sep 1, 2026)
- Arc Help: Arc Search for iOS release notes (iPad layout, June 20, 2024)
- TidBITS: Arc Search iPhone app now syncs Arc sidebar tabs (2024-04-29)
- 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.