Helium vs Zen Browser for Arc Users (2026)

By Kshetez Vinayak, founder of SupaSidebar. Last updated October 26, 2026.

TL;DR

In Helium vs Zen, Zen is the better pick for most Arc users, because it is the only one of the two with Arc-style Spaces, and since September 2026 it syncs them across devices. Helium is an open-source Chromium browser with Arc's vertical tabs, and Zen is an open-source Firefox browser modeled on Arc's whole sidebar. Helium wins for Arc users who want to keep their Chrome extensions, and it already imports Arc's pinned tabs and folders, though only as bookmarks. Zen's catch is the import, because its stable release still cannot read Arc's sidebar, and Arc shuts down on December 22, 2026. The table and a map of where each Arc feature lands are below, plus a third option that keeps either browser and adds Arc's Spaces on top with SupaSidebar.

Quick navigation

• Only weighing Helium against Arc itself? → Helium vs Arc Browser
• Only weighing Zen against Arc itself? → Zen vs Arc Browser
• Comparing Zen with Brave instead? → Zen Browser vs Brave
• Need to save Arc's sidebar before December 22? → How to Export Your Arc Browser Sidebar
• Choosing between Helium and Zen as an Arc user? You are in the right place. Keep reading.

Helium vs Zen at a glance

Why Arc users are weighing Helium against Zen now

Arc stops working on macOS and Windows on December 22, 2026, and accounts are deactivated the same day, according to the Arc farewell page. The Browser Company announced the date on October 22, giving Arc users two months to move, per 9to5Mac's report on Arc's sunset date. For Arc users who do not want Dia, the company's AI-first successor, Helium and Zen are two free, open-source browsers that keep tabs in a sidebar.

The two browsers copy different halves of Arc. Helium copies Arc's look inside Chromium, so tabs move to the side and Chrome extensions keep working. Zen copies Arc's workflow inside Firefox, with Spaces, pinned tabs, folders and Split View.

That split decides most Helium vs Zen questions. An Arc user who lived in one Space will be fine in Helium. One who flipped between Spaces all day will miss them in Helium quickly.

Where Arc's features land in Helium and in Zen

Neither browser keeps Arc's exact model, but Zen keeps far more of it. This map shows where each Arc habit ends up, with SupaSidebar's equivalent alongside.

The Spaces row is where the two browsers part ways. Zen's Spaces hold separate tab sets inside one window, and each Space can get its own default container to keep one account's cookies apart from another's, per Zen's Spaces documentation.

Helium keeps Arc's vertical tabs on Chromium, without Spaces

Helium is the better pick of the two for Arc users who mostly loved Arc's vertical tabs and want to keep their Chrome extensions, because it is Chromium underneath and installs anything from the Chrome Web Store. Helium is free, open source under GPL-3.0, and strips Google services out of Chromium. Its own site still labels it a beta.

Helium's vertical tabs are one of four layouts listed on helium.computer, alongside split view, tab groups, tab hibernation and more than 13,000 offline !bangs. Ads, trackers and cookie banners are blocked by default, and Chrome Web Store requests are anonymized through Helium's own services, per the same page.

Helium also ships fast. Helium 0.20.1.1 for macOS arrived on October 22, 2026 on Chromium 156, with separate builds for Apple silicon and Intel Macs. The project's main repository has more than 22,000 stars.

Helium already imports Arc, which most Helium vs Zen comparisons miss. The Arc importer Helium merged in March 2026 reads Arc's sidebar file and brings Favorites into the bookmarks bar, and each Space's pinned tabs and folders into a bookmarks folder. They arrive as bookmarks because Helium has nowhere else to put them. In the importer's current code, folders for Spaces other than the default Personal one are labeled with Arc's internal Space ID instead of the Space's name, so expect to rename them.

The catch is everything Arc did beyond the tab strip. Helium has no Spaces, so switching from a work context to a personal one means scrolling a single tab list or juggling tab groups. That missing Spaces layer is what SupaSidebar adds on top of Helium, covered below. Helium has no sync either, and its site answers "Not yet" on syncing data between devices. XDA's Helium review also flagged the lack of a built-in password manager.

Zen keeps Arc's Spaces on Firefox, but cannot import Arc yet

Zen is the closer Arc replacement of the two, because it rebuilds Arc's whole sidebar model rather than only its tab strip. Zen has Spaces, pinned tabs, Essentials, folders, Split View and Glance link previews. It is free and open source under the Mozilla Public License 2.0, with more than 45,000 stars on its GitHub repository.

Zen also closed a gap Arc users notice on a second Mac. Zen 1.22b, released September 5, 2026, added sync for Spaces, folders and tabs through a Mozilla account. Arc's own sign-in ends on December 22, so for anyone keeping two Macs in step, that sync is the closest replacement in either browser.

Zen shipped five stable releases in October 2026 alone, the latest being Zen 1.23.4b on October 21. The Zen Browser Mac review covers Mods and performance in more depth.

The first catch is the import. Zen's stable release has no Arc option in its import wizard yet. Zen merged pull request #16130, which turns Arc Spaces into Zen Spaces with their pinned tabs and folders, into its development branch on October 24, 2026, and has not said which release ships it.

The second catch is the engine. Zen runs on Firefox, so Arc's Chrome extensions have to be reinstalled from Mozilla's add-ons store, where a Firefox version exists. Memory use is a common complaint too, though the evidence is anecdotal. One Reddit user who left Zen over high RAM use said they still missed its vertical tabs. No controlled benchmark of Helium against Zen was found, so treat speed claims in either direction as reports, not measurements.

The gap neither browser closes

Helium and Zen make the same assumption, that an Arc user will live in one browser. Plenty never did. Chrome often stays open for a work account, Safari for battery life, and a second browser for testing or a client. Zen's Spaces only exist inside Zen, and Helium has no Spaces at all.

The choice may not be final either. Arc's shutdown shows a browser can be gone two months after a date is announced. A sidebar locked inside one browser has to be rebuilt every time that browser changes.

SupaSidebar adds Arc's Spaces on top of Helium or Zen

SupaSidebar adds Arc's Spaces, pinned items and folders to Helium or Zen as a native Mac sidebar outside the browser, so the Helium vs Zen choice stops being permanent. SupaSidebar is not a browser and not an extension. It is a macOS app that opens each Space's links in the browser that Space points to, across 32+ supported browsers.

SupaSidebar works more deeply with Helium than with Zen. With Helium, it shows open tabs in Live Tabs, so clicking a tab switches to it instead of opening a duplicate, and a Space can link to a specific Helium profile. With Zen, SupaSidebar saves the current page and opens links, but Live Tabs does not cover Zen yet, per the SupaSidebar browser support table. For an Arc user who wants Chromium, Helium plus SupaSidebar is the nearest thing to Arc's sidebar with Spaces.

Arc comes in from Preferences → Import & Export → Arc, and the import guide in SupaSidebar's docs shows how to preview the Spaces and pick which to bring. Choose File accepts a saved copy of Arc's StorableSidebar.json, so a backup still imports after December 22. SupaSidebar 1.3.0 also imports Zen Spaces with their folders and pinned tabs, so a Zen setup can move across later too.

Here is a typical setup for an Arc user who works in Helium and keeps Zen for personal browsing.

Switching Spaces swaps the whole sidebar with one shortcut, and each Space opens its links in its own browser. If Helium or Zen gets dropped next year, the Space is relinked to another browser and nothing is rebuilt. In a review on r/macapps, one user wrote that SupaSidebar "recreates much of that [Arc] experience, but does it across multiple browsers."

SupaSidebar does not move passwords, history or extensions, since those belong to the browser, and it does not change how Helium or Zen render pages. It runs on macOS 14 and later, on Intel and Apple silicon.

Which should you pick, Helium or Zen?

• If Spaces were the reason you used Arc, pick Zen. It is the only one of the two with Spaces, and they sync between Macs.
• If your Chrome extensions are non-negotiable, pick Helium. It runs Chromium extensions, while Zen needs Firefox versions.
• If you want Arc's pinned tabs and folders out before December 22 with no extra steps, Helium imports them today, as bookmarks. Zen's importer has not shipped.
• If you pick Zen now, save a copy of Arc's StorableSidebar.json first, as the Arc sidebar export guide explains, so the data is still there when Zen's importer ships.
• If you want Chromium and Spaces together, use Helium with SupaSidebar on top.

What Arc users should do before December 22

For Arc users choosing between Helium and Zen in late October 2026, Zen is the better Arc replacement, because it keeps Arc's Spaces, pinned tabs and folders as working features and now syncs them between devices. Helium is the better browser for Arc users who mainly want vertical tabs in Chromium with their Chrome extensions intact.

Spaces-heavy Arc users should choose Zen and save Arc's sidebar file now, since Zen's Arc importer is not out. Users who depend on Chrome extensions should choose Helium and run its Arc import this week. Arc users on two Macs should lean toward Zen, since it is the only one of the two that syncs anything between devices today. Arc users who split work across browsers, or want Spaces in Helium, should put Arc's Spaces in SupaSidebar, which imports Arc and Zen and shows Helium's open tabs live.

Whatever the pick, save Arc's sidebar file before December 22. To keep Arc's Spaces on Helium, Zen or both, try SupaSidebar (free version available).

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 32+ browsers including Safari, Chrome, Firefox, Edge, Brave, Vivaldi, Helium, Dia and Orion. It imports Arc's sidebar file and Zen's Spaces, shows Helium's open tabs in Live Tabs, and saves and opens links in Zen. For Arc users torn between Helium and Zen, it keeps one set of Spaces whichever browser stays.

FAQ

Is Helium or Zen better for Arc users?

Zen is better for most Arc users, because it has Arc-style Spaces, pinned tabs, Essentials and folders, and it has synced Spaces through a Mozilla account since September 2026. Helium is better for Arc users who mainly want vertical tabs in a Chromium browser that runs Chrome extensions. Zen's stable release cannot import Arc yet, while Helium imports Arc's pinned tabs and folders as bookmarks.

Does Helium have Spaces like Zen?

No. As of October 2026, Helium has vertical tabs, tab groups and split view, but no Spaces or workspace model. Zen has Spaces that each hold their own tabs inside one window. SupaSidebar can add Spaces on top of Helium, with Helium's open tabs shown in its Live Tabs section.

Can Helium or Zen import from Arc?

Helium can. Its Arc importer brings Arc's Favorites, pinned tabs and folders in as bookmarks, grouped by Space. Zen's stable release, 1.23.4b, cannot import Arc, and the Arc importer Zen merged on October 24, 2026 has no release date yet.

Is Helium lighter than Zen?

User reports lean toward Helium, and Zen draws regular complaints about memory use, but no controlled benchmark of the two was found. Helium is a stripped-down Chromium build without Google services, while Zen is a customized Firefox, and real memory use depends on tabs and extensions.

Do Chrome extensions work in Helium and Zen?

In Helium, yes. Helium is built on Chromium and installs extensions from the Chrome Web Store, with those requests anonymized through Helium's own services. In Zen, no. Zen is built on Firefox, so each extension has to be reinstalled from Mozilla's add-ons store where a Firefox version exists.

How does Brave compare to Helium and Zen?

Brave is Chromium-based like Helium, but it bundles crypto and AI features that Helium leaves out. XDA's Tanveer Singh left Brave over those features, tried Zen, and settled on Helium. Brave and Zen get a full two-way comparison in the Zen Browser vs Brave post.

Are Helium and Zen free and open source?

Yes. Both are free to download and open source, Helium under GPL-3.0 and Zen under the Mozilla Public License 2.0. Helium still describes itself as a beta on its website, so expect missing pieces such as sync.

By Kshetez Vinayak, founder of SupaSidebar. Last updated October 26, 2026.