Zen vs Arc Browser (2026): Which One Should Mac Users Actually Pick

By Kshetez Vinayak, founder of SupaSidebar. Last updated October 28, 2026.

Zen vs Arc: the short answer

Looking for something specific?

• Wondering if Arc is dead and when it stops working? → Is Arc Browser Dead?
• Already decided, ready to leave Arc? → Switching from Arc Browser
• Want the full Zen breakdown? → Zen Browser Mac Review (2026)
• Comparing every alternative? → Arc Browser alternative guide

Why this comparison matters now

The "Zen vs Arc" question only exists because Arc stopped moving. In May 2025, The Browser Company put Arc into maintenance mode, and CEO Josh Miller explained the reasoning bluntly: "for most people, Arc was simply too different, with too many new things to learn, for too little reward." Coverage at the time from The Register and 9to5Mac confirmed development had effectively ended.

The picture got more final later in 2025. Atlassian acquired The Browser Company for $610 million in cash, a deal that closed on October 21, 2025, per BusinessWire. The team's attention is now on Dia, an AI-first browser, not Arc. Then on October 22, 2026, The Browser Company announced that Arc stops working on December 22, 2026, per its Arc Sunset FAQ. Until then Arc keeps working as usual with basic updates, but no new features are coming.

Zen launched in July 2024, right as Arc fans started looking for an exit, and built itself almost entirely around the things people liked about Arc. That timing is why these two get compared so often. This post covers where each one wins on sidebar feel, performance, extensions, and longevity, and then the part both miss: keeping that sidebar workflow when you are not in that one browser.

Which one is still being built

Zen wins on development momentum, and it is not close. As of June 2026, Zen is on version 1.20.x, built on Firefox 151, with releases shipping regularly and new features still landing (a Twilight pre-release channel was testing a customization feature in the same window). The full source lives on GitHub under the MPL-2.0 license at zen-browser/desktop, where it has passed 41,000 stars and become the most-recommended Arc replacement among former Arc users.

Arc is the opposite story. It is stable, but stable in the "frozen" sense, not the "mature and reliable" sense, and now it has an end date. Arc stops working on December 22, 2026, and until then the feature set is whatever shipped before May 2025. For a browser whose entire pitch was experimental new ideas, that is the worst possible outcome. If a browser's longevity matters to a buyer, that single difference decides it.

How the sidebar and Workspaces compare

Zen reproduces Arc's sidebar layout closely, which is the whole point. Both put tabs in a vertical sidebar on the left, both support pinned tabs that persist, and both group browsing into separate contexts: Arc calls them Spaces, Zen calls them Workspaces. Zen adds Split View (up to four tabs in a grid), Compact Mode that hides the sidebar until you need it, and Zen Glance, an alt+click link preview that mirrors Arc's Little Arc peek window.

Arc still has the more refined version of the original. Years of polish show in spacing, animation, and the small interactions, and some long-time users find Zen feels slightly rougher by comparison, more cramped, with font and spacing choices that are not quite as considered. That is a fair criticism, and it is also the kind of thing an actively developed browser can fix, whereas a frozen one cannot. The trade is real polish today versus a moving target that improves over time.

Performance, engine, and extensions

This is where the two genuinely diverge, because they run on different engines. Arc is built on Chromium and Blink, the same engine as Chrome, so it runs Chrome Web Store extensions and behaves like a Chromium browser for site compatibility. Zen is built on Firefox and Gecko, so it uses Firefox add-ons from Mozilla's AMO catalog instead. Neither catalog is "better," but it matters for migration: a Chrome power user moving to Zen has to find Firefox equivalents for their extensions, while moving to Arc keeps the Chrome ecosystem intact.

On the privacy side, a Firefox base gives Zen Firefox's tracking protection and a non-Chromium engine, which some users specifically want as a Chrome alternative. Arc, being Chromium, inherits Chrome-style behavior. There is no single performance winner that holds across every Mac and workload, so the honest framing is engine preference, not raw speed: pick Chromium compatibility (Arc) or a Firefox-based, open-source, privacy-leaning stack (Zen).

The problem neither one solves

Here is the limitation that gets lost in a head-to-head: both Zen and Arc are browsers, so their sidebar only exists while you are inside that browser. The moment you switch to Safari for Apple ecosystem features, or Chrome because work SSO is configured there, the sidebar, the Spaces, and the Workspaces are gone. A typical Mac user is not loyal to one browser. Picking Zen over Arc just moves the sidebar from one walled garden to another.

This is the most common reason Arc users get stuck. As one Reddit user put it: "I would love to try to wean myself off Arc and switch to Safari for full macOS integration. But without Arc sidebar that will never happen." The sidebar workflow, not the browser, is what people are attached to.

SupaSidebar approaches it from the other direction. SupaSidebar is a macOS app that brings Arc's sidebar to every browser, one sidebar for tabs, bookmarks, files, and apps across every major Mac browser including Safari, Chrome, Firefox, Edge, Arc, Brave, Vivaldi, and Dia (32+ browsers in total). It is not a browser and not a browser extension. It is a native Mac app that runs alongside whatever browser is open, with Spaces you can link to specific browser profiles, a Command Panel (⌘⌃K) for cross-browser search, and iCloud sync that needs no account.

The honest limitation worth stating: SupaSidebar's deepest feature, Live Tabs (live mirroring of open tabs across browsers), supports a long list of browsers but Zen is not one of them yet. Alongside Zen, SupaSidebar provides its sidebar, Spaces, Smart Attach, and saved-link organization, with active-tab URL detection rather than full Live Tabs mirroring. With Safari, Chrome, and Brave, Live Tabs is fully supported. For users committed to Zen specifically, that is a real gap to weigh; for everyone running two or more browsers, the cross-browser sidebar is the point.

Which browser should you pick?

• If you loved Arc and want a living browser that keeps the same feel: pick Zen, because it is actively developed, open source, and built around Arc's sidebar and Workspaces.
• If you depend on Chrome extensions and Chromium site behavior: Arc keeps that ecosystem only until it stops working on December 22, 2026. Keep Chrome and add SupaSidebar for the sidebar and Spaces, or move to Dia, The Browser Company's Chromium-based successor.
• If your real attachment is the sidebar, not the browser: the browser choice is secondary. Run whatever browser you like and add SupaSidebar so the sidebar and Spaces follow you across Safari, Chrome, Firefox, and the rest.
• If you run two or more browsers daily: neither Zen nor Arc helps, because each only shows its own tabs. SupaSidebar is built for exactly this, a single sidebar across all of them.

Conclusion: picking between Zen and Arc in 2026

For a Mac user choosing between Zen and Arc today, Zen is the stronger standalone browser because it is the one still being built, it is open source, and it recreates Arc's sidebar and Workspaces while Arc stops working on December 22, 2026. Arc keeps the Chromium extension ecosystem only until then, so it is a place to export your Spaces from, not a place to switch to.

The deeper answer is that the sidebar is the thing worth keeping, not the browser around it. Single-browser users who want Arc's experience in a maintained browser should try Zen. Anyone running more than one browser, or who wants to switch to Safari without losing the sidebar, gets more from a cross-browser sidebar that does not care which browser is in front.

Why we recommend SupaSidebar

SupaSidebar is a macOS app that brings Arc's sidebar to every browser, one sidebar for tabs, bookmarks, files, and apps across every major Mac browser including Safari, Chrome, Firefox, Edge, Arc, Brave, Vivaldi, and Dia (32+ browsers in total). It is a native Mac app, not a browser and not a browser extension, so the choice between Zen and Arc stops being all-or-nothing: keep your browser, and let the sidebar, Spaces, and Command Panel work across all of them. There is a free version available. Try SupaSidebar (free tier).

Want SupaSidebar side by side with each browser? See SupaSidebar vs Zen and SupaSidebar vs Arc.

FAQ

Is Zen better than Arc in 2026?

For most users, yes. Zen is actively developed and open source, while Arc stops working on December 22, 2026, after a year and a half in maintenance mode. Zen recreates Arc's vertical sidebar, Workspaces, and split view on a Firefox base. Arc keeps Chromium extensions until then, but it is a browser to leave, not one to grow into. If you'd rather keep Chrome or Safari, SupaSidebar adds Arc's sidebar and Spaces to the browser you already use.

What happened to Arc Browser?

The Browser Company put Arc into maintenance mode in May 2025, then was acquired by Atlassian for $610 million in a deal that closed on October 21, 2025. The team now works on a different AI-first browser, Dia. On October 22, 2026, the company announced that Arc stops working on macOS and Windows on December 22, 2026, and that every Arc account will be deactivated that day.

Is Zen Browser based on Chrome or Firefox?

Zen is built on Firefox (the Gecko engine), so it uses Firefox add-ons from Mozilla's AMO catalog, not Chrome Web Store extensions. Arc is built on Chromium (Blink), the same engine as Chrome. This is the main migration consideration: Chrome power users keep their extensions on Arc but must find Firefox equivalents on Zen.

Can I keep an Arc-style sidebar if I switch browsers?

Yes, but not by switching to another browser, since each browser's sidebar only works inside that browser. SupaSidebar is a Mac app that adds an Arc-style sidebar to any browser, including Safari, Chrome, Firefox, and Arc, so the sidebar and Spaces follow you regardless of which browser is open.

Does SupaSidebar work with Zen Browser?

Partially. SupaSidebar provides its sidebar, Spaces, Smart Attach, and link organization alongside Zen, with active-tab URL detection. Its full Live Tabs mirroring (which shows every open tab across browsers in real time) supports many browsers but not Zen yet. With browsers like Safari, Chrome, and Brave, Live Tabs is fully supported.

Is Arc still safe to use in 2026?

Only until December 22, 2026. Arc keeps receiving basic updates until then, per The Browser Company, but on December 22 it stops working on macOS and Windows and every account is deactivated. That is why most Arc users are moving now, to Zen, to Dia, or to the browser they already use with SupaSidebar added.

By Kshetez Vinayak, founder of SupaSidebar. Last updated October 28, 2026.