Wren
Mac Chromium browser with a Rust core: Spaces with profiles, nested pin folders, bundled uBlock Origin.
Wren is a free Mac browser by Multibox Labs (Avocado and Bear Limited), the rewrite of Flow (Electron, GPL-3.0, flow-browser.com) from the ground up. A Rust main process drives Chromium 157 through Wren Runtime, a closed library; the sidebar, omnibox and dialogs are React pages at wren://. Spaces each have their own pins, theme and a profile that other spaces can share, with favourites, nested folders, two-pane split view, a ⌃Tab switcher, an omnibox with 10,000+ bangs and bundled uBlock Origin (MV2) on by default. Chrome Web Store extensions install. It imports Arc spaces, favourites, pins and folders. The app is MPL-2.0 but Wren Runtime is not open source. Only Apple silicon macOS 13+; the first release 0.8.0 (2026-11-14) is beta. Anonymous feature counts and crash reports go to PostHog unless switched off; browsing never does. Peek, Mini Wren, Boosts, live folders and auto-PiP are on the roadmap.
Bloat check
1 thing you didn't ask for
- Telemetry on by defaultAnonymous feature counts and crash reports go to PostHog (EU) once per launch, on by default; Help Improve Wren turns it off. No browsing data.github.com
No ads, wallet, feed, upsell or account. The ad blocker, Chromium's password manager and autofill start on.
Ads, crypto, paid upsells, news feeds, default-on telemetry, required accounts.
Organization
| Feature | Wren | Arc | Note |
|---|---|---|---|
| SidebarVertical sidebarTabs live in a vertical sidebar that is the main tab UI and can be hidden. | ✓ | ✓ | Tabs live in Wren's own sidebar (React pages, no Chrome tab strip); View > Toggle Sidebar (⌘S) hides it.github.com |
| SpacesSeveral workspaces per window, each with its own pinned and open tabs, switched by swipe or shortcut. | ✓ | ✓ | Each space keeps its own pins and tabs; swipe the sidebar or press ⌃1 to ⌃9 to switch, and drag a tab onto another space.github.com |
| ProfilesProfiles per Space (shareable)Each Space can use its own browser profile (separate cookies, logins, history), and one profile can be shared by several Spaces. | ✓ | ✓ | A new space picks any profile (or makes one); spaces in the same profile share sign-ins, cookies and history, others stay apart.github.com |
| FavoritesGlobal favoritesPinned icons at the top of the sidebar shared by every Space (Zen calls them Essentials). | ✓ | ✓ | Favourite tiles sit above the pins, three to a row, shared by every space of a profile; each profile keeps its own set.github.com |
| Pinned TabsPinned tabs & foldersPer-space pinned tabs that act like bookmarks, with nested folders. | ✓ | ✓ | Each space has its own pins and folders; folders nest (into another folder, never into themselves) and live only among a space's pins.github.com |
| Live foldersSidebar folders that fill and refresh themselves from an outside source, such as GitHub pull requests or an RSS feed. | ✕ | ✓ | Live Folders are listed as planned on the roadmap; none in the app.wrenbrowser.com |
| ArchiveAuto-archive tabsUnpinned tabs close automatically after a set time and stay recoverable in an archive. | ◐ | ✓ | Unpinned background tabs close after 12 hours unused (or 24 h, 7 d, 30 d, in Settings); there is no archive to browse, only Reopen Closed Tab.github.com |
| Theme pickerSpace themesPer-space colour or gradient themes. | ✓ | ✓ | Each space has its own theme: one to three colours, grain strength, light, dark or system, plus an icon or emoji.github.com |
Browsing
| Feature | Wren | Arc | Note |
|---|---|---|---|
| Split ViewTwo or more tabs side by side in one window. | ◐ | ✓ | Two tabs side by side or stacked as one sidebar row with a draggable divider; a split holds exactly two tabs.github.com |
| PeekLink previewOpen a link in an overlay without leaving the current page (Zen calls it Glance). | ✕ | ✓ | Peek Tabs are planned on the roadmap; links open as ordinary tabs.wrenbrowser.com |
| Little ArcMini windowA small, chrome-less window for links opened from other apps or a quick search. | ✕ | ✓ | Mini Wren is planned on the roadmap; links from other apps open as a new tab in the window you browse in.wrenbrowser.com |
| Command barA ⌘T palette that searches tabs, history, bookmarks and browser commands. | ◐ | ✓ | ⌘T opens a centred omnibox: open tabs, history, Chromium's suggestions and 10,000+ bangs; it runs no browser commands.github.com |
| Air Traffic ControlLink routingRules that send links from other apps to a chosen space or profile. | ✕ | ✓ | Links from other apps open as a new tab in the window you browse in; no per-site rules and no default space.github.com |
| BoostsSite customizationPer-site custom CSS/JS, or zapping elements off a page. | ✕ | ✓ | Boosts are a commented-out TODO in the Library; Wren Tweaks (site styles and scripts) are planned on the roadmap.github.com |
| Auto PiPAuto picture-in-picturePlaying video pops out into picture-in-picture automatically when you switch tabs. | ◐ | ✓ | Chromium's picture-in-picture windows exist, but leaving a tab does not pop the video out; Auto Picture-in-Picture is planned.github.com |
| Mini playerMedia still playing in a tab you left keeps play/pause controls in the sidebar. | ✕ | ✓ | Playing media (controls at the bottom of the sidebar) is planned on the roadmap.wrenbrowser.com |
| Tab SwitcherRecent-tab switcherCtrl+Tab jumps back to the tab you used last and cycles in recently used order. | ✓ | ✓ | ⌃Tab shows the five last-used tabs of the space as cards; keep Control held to step on, release to go; ⌃⇧Tab goes back.github.com |
| Super CopyClean link copyA shortcut (⌘⇧C) copies the page URL with tracking parameters removed. | ◐ | ✓ | Copy URL (⇧⌘C) copies the page address with a toast, but no tracker removal (no utm_ or fbclid handling in the source).github.com |
| CaptureScreenshotsBuilt-in capture of a chosen area or element, and of the full page. | ✕ | ✓ | No area, element or full-page capture in the menus or source; DevTools screenshots do not count.github.com |
Compatibility & migration
| Feature | Wren | Arc | Note |
|---|---|---|---|
| Arc importImports Arc spaces, pinned tabs and folders. | ✓ | – | Imports Arc's spaces with icon and theme, favourites, pinned tabs, folders and splits, plus profiles, bookmarks, history and cookies.github.com |
| Chrome extensionsInstalls extensions from the Chrome Web Store. | ✓ | ✓ | Installs from the Chrome Web Store: the store's "Add to Chrome" reads "Add to Wren"; side panels run too (site claim).github.com |
| DRM streamingNetflix, Disney+, Spotify web and other DRM video/audio play, through Widevine or, on WebKit, FairPlay. Chromium forks need a Google Widevine licence; FairPlay counts once a major service is confirmed playing in the app. | ? | ✓ | |
| PasskeysWebAuthn passkeys, Touch ID and the system/iCloud keychain. | ◐ | ✓ | No browser passkey entitlement in the signed app, so passkeys fall back to Chromium's own WebAuthn, not the system keychain (not exercised).github.com |
| SyncSpaces, pinned tabs and settings sync across devices. | ✕ | ✓ | No sync of spaces, pins or settings between devices; Wren is Mac-only.wrenbrowser.com |
| Mobile appiPhone, iPad or Android app that shares spaces with desktop. | ✕ | ◐ | Mac only (Apple silicon, macOS 13+); Windows and Linux are on the roadmap, no iPhone, iPad or Android app.wrenbrowser.com |
Extras
| Feature | Wren | Arc | Note |
|---|---|---|---|
| Built-in ad blockerAd and tracker blocking without installing an extension. | ✓ | ✓ | Bundled uBlock Origin 1.76.2 is on in every new profile and in incognito windows; each profile can switch it off in Profiles.github.com |
| Custom ShortcutsShortcut editorMost browser keyboard shortcuts can be remapped in Settings. | ✕ | ✓ | Custom keybinds are planned on the roadmap; Settings has no shortcut page.wrenbrowser.com |
More Arc features
Arc features shown but not counted in the score, because almost no replacement has them or only a few people need them.
| Feature | Wren | Arc | Note |
|---|---|---|---|
| EaselsA shareable canvas of live page captures, notes and drawings. | ✕ | ◐ | No Easels or shared canvases.github.com |
| Shared CollectionsShared spaces & foldersShare a Space, folder or set of tabs as a link anyone can open, or another user can add to their sidebar. | ✕ | ✓ | A space, folder or pin set cannot be shared as a link or file.github.com |
| PreviewsWeb app previewsHover a pinned Gmail, Calendar or other web app to glance at it; a pinned calendar shows the next meeting with Join. | ✕ | ✓ | No pinned-web-app previews; a favourite is just a tile.github.com |
| Developer modeA developer view that turns on by itself for localhost: full URL, quick DevTools and dev tools in reach. | ◐ | ✓ | View menu has Developer Tools, JavaScript Console, Inspect Elements and View Source (Chromium's, DevTools in its own window); nothing turns on for localhost.github.com |
Extension support
Which extension formats and stores run, beyond the Chrome Web Store row above.
| Feature | Wren | Arc | Note |
|---|---|---|---|
| Manifest V2 extensionsThe older extension format Chrome removed in 2025. Needed for full uBlock Origin and other extensions that block requests. | ◐ | ✕ | Only the bundled uBlock Origin (Manifest V2, allow-listed by ID) runs as MV2; no other MV2 extension is allowed.github.com |
| Manifest V3 extensionsThe current extension format used by the Chrome Web Store (and supported by Firefox and Safari). | ✓ | ✓ | Chromium 157 extension host with Chrome Web Store install and side panels (site claim); MV3 API coverage not tested.github.com |
| Firefox add-onsAdd-ons from addons.mozilla.org or .xpi files install and run. | ✕ | ✕ | Chromium extensions only; no .xpi or addons.mozilla.org path.github.com |
| Safari extensionsSafari web extensions (the App Store extension apps Safari uses) install and run. | ✕ | ✕ | Chromium extensions only; no Safari extension support.github.com |