Tern
Free Mac browser with Spaces, Desks and an ask-first Claude agent; imports Arc Spaces, syncs through iCloud.
Tern is a closed-source, Mac-only browser by the Front Tribe studio in Osijek, Croatia, and its website has a guide for moving over from Arc. Each Space has its own colour, sign-ins, pinned tabs and folders, Desks (two to four pages side by side that can be saved and reopened with ⌥1 to ⌥9), Today tabs that sleep after an hour, notes and tasks. It has Shift-click link previews, a command bar, per-app and per-site link rules that send links to a Space, a little window for links from other apps, a built-in EasyList/EasyPrivacy blocker, and Chrome Web Store extensions. It imports Arc Spaces, pinned tabs and folders from Arc's sidebar file, and Spaces, pinned tabs, folders, Desks and notes sync through iCloud. An optional agent in every Space runs on your own Claude key and asks before it books, pays or sends. New installs use a layout with a bottom bar and a hover shelf at the left edge; the classic sidebar is an optional setting. It needs macOS 26, has no passkey support yet, and its iPhone app is not on the App Store yet. Engine is not stated; it looks like system WebKit. This entry rests on Tern's docs, release notes and release feed; the app was not downloaded.
67% Arc feature parity (yes = 1, partial = ½).
AI optional
The agent in every Space stays off until you turn it on and add your own Claude API key (or a coding-agent plan); it asks before acting.
ternbrowser.comNot counted in Arc parity: some people want AI, some avoid it.
None found
Crash reports and usage statistics are opt-in; update checks are counted by version only. No account, ads or paid tier found; the agent uses your own key.
ternbrowser.comAds, crypto, paid upsells, news feeds, default-on telemetry, required accounts.
Organization
| Feature | Tern | Arc | Note |
|---|---|---|---|
| Vertical sidebarTabs live in a vertical sidebar that is the main tab UI and can be hidden. | ◐ | ✓ | New installs use a bottom bar plus a hover shelf at the left edge; the classic sidebar layout is optional.ternbrowser.com |
| SpacesSeveral workspaces per window, each with its own pinned and open tabs, switched by swipe or shortcut. | ✓ | ✓ | Each Space has its own pinned tabs, Today tabs and Desks; ⌃←/⌃→ or a two-finger swipe moves between them.ternbrowser.com |
| Profiles per Space (shareable)Each Space can use its own browser profile (separate cookies, logins, history), and one profile can be shared by several Spaces. | ◐ | ✓ | Every Space keeps its own cookies and sign-ins, but a profile cannot be shared across Spaces.ternbrowser.com |
| Global favoritesPinned icons at the top of the sidebar shared by every Space (Zen calls them Essentials). | ◐ | ✓ | Favourites are tiles on a Space's shelf and belong to each Space; none are shared across Spaces.ternbrowser.com |
| Pinned tabs & foldersPer-space pinned tabs that act like bookmarks, with nested folders. | ✓ | ✓ | Per-Space pinned tabs that stay when closed, with folders and folders inside folders.ternbrowser.com |
| Auto-archive tabsUnpinned tabs close automatically after a set time and stay recoverable in an archive. | ◐ | ✓ | Unused tabs sleep after 15 min to 2 h (default 1 h); they stay open, and there is no archive of old tabs.ternbrowser.com |
| Space themesPer-space colour or gradient themes. | ✓ | ✓ | Each Space has its own colour and icon, and the window takes on the colour of the Space.ternbrowser.com |
Browsing
| Feature | Tern | Arc | Note |
|---|---|---|---|
| Split ViewTwo or more tabs side by side in one window. | ✓ | ✓ | Two, three or four pages in one window; save the layout as a Desk and reopen it with ⌥1 to ⌥9.ternbrowser.com |
| Link previewOpen a link in an overlay without leaving the current page (Zen calls it Glance). | ✓ | ✓ | Shift-click a link to open it in a preview over the page; keep it as a tab, open it beside, or close it.ternbrowser.com |
| Mini windowA small, chrome-less window for links opened from other apps or a quick search. | ✓ | ✓ | A link from another app opens first in a little window over that app, in its Space; can be turned off.ternbrowser.com |
| Command barA ⌘T palette that searches tabs, history, bookmarks and browser commands. | ✓ | ✓ | ⌘T bar finds Spaces, open tabs, pinned pages, history and actions together; Tab sends the words to the agent.ternbrowser.com |
| Link routingRules that send links from other apps to a chosen space or profile. | ✓ | ✓ | Per-Space rules send links from an app or a site to that Space, or ask each time.ternbrowser.com |
| Site customizationPer-site custom CSS/JS, or zapping elements off a page. | ✕ | ✓ | No per-site CSS/JS or zap feature in the docs, and no Boost or custom-CSS strings in the 1.2.0 binary.ternbrowser.com |
| Auto picture-in-picturePlaying video pops out into picture-in-picture automatically when you switch tabs. | ? | ✓ |
Compatibility & migration
| Feature | Tern | Arc | Note |
|---|---|---|---|
| Arc importImports Arc spaces, pinned tabs and folders. | ✓ | – | Reads Arc's sidebar file for Spaces, pinned tabs, folders, favorites and extensions; no Arc account needed.ternbrowser.com |
| Chrome extensionsInstalls extensions from the Chrome Web Store. | ✓ | ✓ | Installs from the Chrome Web Store with signature checks and updates; off in private windows.ternbrowser.com |
| DRM (Widevine)Netflix, Disney+, Spotify web and other DRM video/audio play. Chromium forks need a Google Widevine licence. | ? | ✓ | |
| PasskeysWebAuthn passkeys, Touch ID and the system/iCloud keychain. | ✕ | ✓ | Release notes: Tern can't use passkeys in this version; a note over the page tells you to sign in another way.ternbrowser.com |
| SyncSpaces, pinned tabs and settings sync across devices. | ✓ | ✓ | Spaces, pinned tabs, folders, open tabs and Desks sync through your own iCloud; sign-ins and history do not.ternbrowser.com |
| Mobile appiPhone, iPad or Android app that shares spaces with desktop. | ✕ | ◐ | Tern for iPhone is listed as coming soon to the App Store; no downloadable iPhone app yet.ternbrowser.com |
Extras
| Feature | Tern | Arc | Note |
|---|---|---|---|
| Built-in ad blockerAd and tracker blocking without installing an extension. | ✓ | ✓ | Ads and trackers are blocked in every Space from the start, using bundled EasyList and EasyPrivacy.ternbrowser.com |
Extension support
Which extension formats and stores run, beyond the Chrome Web Store row above. Not counted in Arc parity.
| Feature | Tern | Arc | Note |
|---|---|---|---|
| Manifest V2 extensionsThe older extension format Chrome removed in 2025. Needed for full uBlock Origin and other extensions that block requests. | ◐ | ✕ | WKWebExtension loads MV2 but WebKit ignores blocking webRequest, so full uBlock Origin can't block.github.com |
| Manifest V3 extensionsThe current extension format used by the Chrome Web Store (and supported by Firefox and Safari). | ✓ | ✓ | Chrome Web Store extensions install and run; not every extension was tested by us.ternbrowser.com |
| Firefox add-onsAdd-ons from addons.mozilla.org or .xpi files install and run. | ✕ | ✕ | Extensions come only from the Chrome Web Store; the 1.2.0 binary has no .xpi or addons.mozilla.org path.ternbrowser.com |
| Safari extensionsSafari web extensions (the App Store extension apps Safari uses) install and run. | ✕ | ✕ | No Safari extension (appex) discovery; Chrome Web Store is the only extension source.ternbrowser.com |