Contrail
Free WebKit sidebar browser for Mac, iPhone and iPad with Spaces, Arc import, live folders and iCloud sync.
Contrail is a free, closed-source browser by a solo developer, built on Apple's WebKit for Mac (0.11 nightly; latest beta 0.10.1) with an iPhone and iPad public beta on TestFlight. Tabs live in a sidebar grouped into Spaces; each Space has its own gradient theme and uses a profile that several Spaces can share, and Favorites sit above every Space. Unpinned Today tabs move to an Archive after a set time, Glance previews links over the page, Gliders are small windows for links from other apps, routes send links to a chosen Space, and a window splits into up to four panes. It imports Arc Spaces, pinned tabs, folders, splits and Favorites from Arc's sidebar file, installs Chrome Web Store extensions, blocks ads with uBlock Origin and Brave lists, and has GitHub pull-request live folders plus Canvases and Notes. A Mini Player in the sidebar controls media from other tabs. Sync through your own iCloud is opt-in. The maker plans to move to Chromium once Google approves Widevine.
Built-in AI
AI optional
Only Apple's on-device model (tab titles, download names, Tidy; all off by default) and macOS Translation. Nothing goes to an AI service.
contrailbrowser.comBloat check
None found
No account, analytics, ads or paid tier. Mac crash reports are opt-in; update checks send only name and version.
contrailbrowser.comAds, crypto, paid upsells, news feeds, default-on telemetry, required accounts.
Organization
| Feature | Contrail | Arc | Note |
|---|---|---|---|
| SidebarVertical sidebarTabs live in a vertical sidebar that is the main tab UI and can be hidden. | ✓ | ✓ | Tabs live in a vertical sidebar with Favorites, pinned tabs and Today tabs; a setting moves it to the right.contrailbrowser.com |
| SpacesSeveral workspaces per window, each with its own pinned and open tabs, switched by swipe or shortcut. | ✓ | ✓ | Each Space has its own tabs, pinned items and theme; shortcuts switch to the next, previous or a numbered 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. | ✓ | ✓ | Each Space uses one profile (own cookies, logins, history, extensions), and several Spaces can share it.github.com |
| FavoritesGlobal favoritesPinned icons at the top of the sidebar shared by every Space (Zen calls them Essentials). | ✓ | ✓ | Favorites sit at the top of the sidebar in every Space; like Arc, they belong to the profile.github.com |
| Pinned TabsPinned tabs & foldersPer-space pinned tabs that act like bookmarks, with nested folders. | ✓ | ✓ | Per-Space pinned tabs with folders; Arc import keeps pinned tabs and folders as they are.contrailbrowser.com |
| Live foldersSidebar folders that fill and refresh themselves from an outside source, such as GitHub pull requests or an RSS feed. | ✓ | ✓ | A GitHub Live Folder lists your open pull requests and review requests and updates on its own, using the profile's sign-in.contrailbrowser.com |
| ArchiveAuto-archive tabsUnpinned tabs close automatically after a set time and stay recoverable in an archive. | ✓ | ✓ | Unpinned Today tabs move to the Archive after 12 hours by default; the time can differ per profile.contrailbrowser.com |
| Theme pickerSpace themesPer-space colour or gradient themes. | ✓ | ✓ | Every Space has its own theme with a multi-colour gradient editor; pages can read the theme as CSS variables.github.com |
Browsing
| Feature | Contrail | Arc | Note |
|---|---|---|---|
| Split ViewTwo or more tabs side by side in one window. | ✓ | ✓ | Up to four pages side by side or stacked in one window.contrailbrowser.com |
| PeekLink previewOpen a link in an overlay without leaving the current page (Zen calls it Glance). | ✓ | ✓ | Glance opens a link in a floating panel over the page; Shift-click, and links to other sites from Favorites and pinned tabs.contrailbrowser.com |
| Little ArcMini windowA small, chrome-less window for links opened from other apps or a quick search. | ✓ | ✓ | Gliders are small windows for one page; onboarding says links from other apps open in one, and a shortcut opens one from any app.github.com |
| Command barA ⌘T palette that searches tabs, history, bookmarks and browser commands. | ✓ | ✓ | Command Bar takes an address or search, or picks an open tab, history page or browser command.github.com |
| Air Traffic ControlLink routingRules that send links from other apps to a chosen space or profile. | ✓ | ✓ | Routes send links from other apps that contain given text to a chosen Space; the rest follow a default.github.com |
| BoostsSite customizationPer-site custom CSS/JS, or zapping elements off a page. | ◐ | ✓ | Zap only: click anything on a page to hide it on that site. No per-site CSS or JS editor.github.com |
| Auto PiPAuto picture-in-picturePlaying video pops out into picture-in-picture automatically when you switch tabs. | ✓ | ✓ | Setting "Keep a playing video in Picture in Picture when you switch tabs", on by default.github.com |
| Mini playerMedia still playing in a tab you left keeps play/pause controls in the sidebar. | ✓ | ✓ | Sidebar Mini Player for media in another tab: play/pause, previous/next (where supported), volume, Picture in Picture and Back to Tab.github.com |
| Tab SwitcherRecent-tab switcherCtrl+Tab jumps back to the tab you used last and cycles in recently used order. | ✓ | ✓ | Ctrl+Tab opens a switcher on your most recently used tabs; keep holding Control and press Tab to move along.github.com |
| Super CopyClean link copyA shortcut (⌘⇧C) copies the page URL with tracking parameters removed. | ✓ | ✓ | Copy Current URL (⌥⇧⌘C) copies the address with known tracking parameters taken out; a Markdown-link variant strips them too.github.com |
| CaptureScreenshotsBuilt-in capture of a chosen area or element, and of the full page. | ✓ | ✓ | Page menu has Capture part of this page (hold a key and drag across the page) and Capture the whole page.github.com |
Compatibility & migration
| Feature | Contrail | Arc | Note |
|---|---|---|---|
| Arc importImports Arc spaces, pinned tabs and folders. | ✓ | – | Reads Arc's sidebar file: Spaces with colours, pinned tabs, folders, splits and Favorites, plus history, cookies and extensions.contrailbrowser.com |
| Chrome extensionsInstalls extensions from the Chrome Web Store. | ✓ | ✓ | On the Mac, installs from the Chrome Web Store with signature and version checks, and updates them.contrailbrowser.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. | ? | ✓ | System WebKit, no Widevine (the Chromium switch waits on Google's approval); FairPlay playback not tested.contrailbrowser.com |
| PasskeysWebAuthn passkeys, Touch ID and the system/iCloud keychain. | ✕ | ✓ | Roadmap: passkeys wait on Apple; the 0.11 nightly bundle lacks Apple's browser passkey entitlement.contrailbrowser.com |
| SyncSpaces, pinned tabs and settings sync across devices. | ✓ | ✓ | Opt-in iCloud sync of Spaces, tabs, Favorites, settings, history, Notes and Canvases; profiles other than Default don't sync.contrailbrowser.com |
| Mobile appiPhone, iPad or Android app that shares spaces with desktop. | ◐ | ◐ | iPhone and iPad app shares Spaces through iCloud, but it is a public beta on TestFlight.testflight.apple.com |
Extras
| Feature | Contrail | Arc | Note |
|---|---|---|---|
| Built-in ad blockerAd and tracker blocking without installing an extension. | ✓ | ✓ | Built-in blocker (adblock-rust) with uBlock Origin, Brave, EasyList and URLhaus lists; blocks ads and trackers with nothing to install.contrailbrowser.com |
| Custom ShortcutsShortcut editorMost browser keyboard shortcuts can be remapped in Settings. | ✓ | ✓ | Settings Shortcuts pane: edit any action's keys, search by action or keys, restore defaults, and clear clashes with other actions.github.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 | Contrail | Arc | Note |
|---|---|---|---|
| EaselsA shareable canvas of live page captures, notes and drawings. | ◐ | ◐ | Canvases hold text, shapes, images and live, signed-in web cards and sync through iCloud; no sharing link found.contrailbrowser.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. | ◐ | ✓ | No Space or folder sharing found; Live Folders offer Copy Links as Markdown List, and the macOS share menu shares one page address.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. | ✓ | ✓ | Hover a Favorite or Pinned tab to see Gmail unread mail, or recent pages for Notion, Linear, Figma and Confluence; Favorites show unread dots.github.com |
| Developer modeA developer view that turns on by itself for localhost: full URL, quick DevTools and dev tools in reach. | ✓ | ✓ | Developer Mode switches on per site, with default hosts you can turn off; adds Inspect Elements, JavaScript Console and Network Inspector commands.github.com |
Extension support
Which extension formats and stores run, beyond the Chrome Web Store row above.
| Feature | Contrail | 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 on the Mac; not every extension was tested by us.contrailbrowser.com |
| Firefox add-onsAdd-ons from addons.mozilla.org or .xpi files install and run. | ✕ | ✕ | Extensions come from the Chrome Web Store or an unpacked folder; no .xpi or addons.mozilla.org path in the binary.github.com |
| Safari extensionsSafari web extensions (the App Store extension apps Safari uses) install and run. | ✕ | ✕ | No Safari extension (appex) discovery in the Mac app; iPhone and iPad extensions were not checked.github.com |