Phi
Chromium browser with an Arc-style sidebar, Spaces over Profiles, URL Rules and a built-in AI assistant.
Phi is a Chromium-based browser from Phinomenon Inc. with a native macOS client written in Swift (AppKit and SwiftUI). It keeps a vertical sidebar, Spaces layered over Profiles, Split View, Peek and URL Rules, and it can migrate Arc Profiles and Spaces directly from the Mac. AI features (assistant, local Memory, background tasks) are on by default after sign-in and can be switched off. The macOS and Windows clients are Apache-2.0 on GitHub, while the Chromium engine build ships as a proprietary binary; Windows is an early-access build.
Built-in AI
AI on by default
Assistant, Memory and agent tasks are on out of the box after sign-in; one switch in Settings turns all AI off. Skipping sign-in gives a plain browser.
phibrowser.comBloat check
1 thing you didn't ask for
- Telemetry on by defaultAnonymous PostHog counts have no off switch. Usage stats and Sentry crash reports are opt-out: the onboarding box is pre-ticked outside Europe.github.com
No ads, wallet, feed or upsells found. Account is optional ('Explore without signing in'). Help page says stats are off by default; FAQ and code say on.
Ads, crypto, paid upsells, news feeds, default-on telemetry, required accounts.
Organization
| Feature | Phi | Arc | Note |
|---|---|---|---|
| SidebarVertical sidebarTabs live in a vertical sidebar that is the main tab UI and can be hidden. | ✓ | ✓ | Sidebar is the main UI; Comfortable layout mode moves tabs back to a top strip.phibrowser.com |
| SpacesSeveral workspaces per window, each with its own pinned and open tabs, switched by swipe or shortcut. | ✓ | ✓ | Spaces have own bookmarks, theme and icon; pinned-tab scope is configurable.phibrowser.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 belongs to one Profile; one Profile can back several Spaces; new Profile can be created per Space.github.com |
| FavoritesGlobal favoritesPinned icons at the top of the sidebar shared by every Space (Zen calls them Essentials). | ✓ | ✓ | Pinned tab scope "App" shares them across all Spaces and Profiles; default scope is Profile.phibrowser.com |
| Pinned TabsPinned tabs & foldersPer-space pinned tabs that act like bookmarks, with nested folders. | ◐ | ✓ | Pinned tabs are a flat grid; folders exist for per-Space bookmarks that open in place.github.com |
| Live foldersSidebar folders that fill and refresh themselves from an outside source, such as GitHub pull requests or an RSS feed. | ✕ | ✓ | No live-folder code at 28df0d0 and no live-folder strings in Canary 970; the item model has only tab, pinned tab, bookmark and bookmark folder.github.com |
| ArchiveAuto-archive tabsUnpinned tabs close automatically after a set time and stay recoverable in an archive. | ✕ | ✓ | Only manual Clear All Tabs; auto-close of idle tabs is an open feature request (#255).github.com |
| Theme pickerSpace themesPer-space colour or gradient themes. | ✓ | ✓ | Each Space can have its own colour theme or follow the global one.phibrowser.com |
Browsing
| Feature | Phi | Arc | Note |
|---|---|---|---|
| Split ViewTwo or more tabs side by side in one window. | ✓ | ✓ | Canary 970: splits of two to four panes, side by side or stacked, with pane move, swap and close menus; a split can be pinned or bookmarked as one item. Stable 2.16.1 is two-pane only.ota.phibrowser.com |
| PeekLink previewOpen a link in an overlay without leaving the current page (Zen calls it Glance). | ✓ | ✓ | Peek View floating panel; automatic for cross-site links from pinned tabs/bookmarks, else Shift-click.phibrowser.com |
| Little ArcMini windowA small, chrome-less window for links opened from other apps or a quick search. | ✓ | ✓ | Kiosk window; external links open there via a Settings toggle.phibrowser.com |
| Command barA ⌘T palette that searches tabs, history, bookmarks and browser commands. | ◐ | ✓ | Cmd+T opens a new tab only; searching open tabs is a separate shortcut (Cmd+Shift+A).github.com |
| Air Traffic ControlLink routingRules that send links from other apps to a chosen space or profile. | ✓ | ✓ | URL Rules by domain/URL send links to a Space, Incognito or Kiosk, or ask each time.github.com |
| BoostsSite customizationPer-site custom CSS/JS, or zapping elements off a page. | ✕ | ✓ | Canary 970: no Boosts, zap or per-site CSS/JS strings in the client or UI resources; extensions only.ota.phibrowser.com |
| Auto PiPAuto picture-in-picturePlaying video pops out into picture-in-picture automatically when you switch tabs. | ✓ | ✓ | Auto picture-in-picture: Off, Normal (default; on tab or app switch) or Park at edge.github.com |
| Mini playerMedia still playing in a tab you left keeps play/pause controls in the sidebar. | ✓ | ✓ | Sidebar player for background media has previous, play/pause, next, mute and volume; on by default.github.com |
| Tab SwitcherRecent-tab switcherCtrl+Tab jumps back to the tab you used last and cycles in recently used order. | ✓ | ✓ | Ctrl+Tab opens the switcher in recently-used order (up to five tabs); Ctrl+Shift+Tab reverses. Default binding, rebindable.github.com |
| Super CopyClean link copyA shortcut (⌘⇧C) copies the page URL with tracking parameters removed. | ◐ | ✓ | ⌘⇧C copies the current URL; the copy path only rewrites chrome:// to phi://, no tracking-parameter stripping.github.com |
| CaptureScreenshotsBuilt-in capture of a chosen area or element, and of the full page. | ✓ | ✓ | File menu and defaults: Capture Full Page ⌘⇧1 and Capture Area ⌘⇧2; the PNG is copied and opens an editor.github.com |
Compatibility & migration
| Feature | Phi | Arc | Note |
|---|---|---|---|
| Arc importImports Arc spaces, pinned tabs and folders. | ✓ | – | Parses Arc StorableSidebar.json (Spaces, pins); history, cookies, extensions copied; no passwords import type.github.com |
| Chrome extensionsInstalls extensions from the Chrome Web Store. | ✓ | ✓ | Installs from the Chrome Web Store; extensions are per Profile.phibrowser.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. | ✓ | ✓ | Canary 970: CDM helper + Widevine component updater, no bundled WidevineCdm; Netflix named in 2.13.0 notes.ota.phibrowser.com |
| PasskeysWebAuthn passkeys, Touch ID and the system/iCloud keychain. | ✓ | ✓ | Canary 970: web-browser.public-key-credential entitlement and a webauthn keychain group; iCloud Keychain passkey code in Chromium 156.ota.phibrowser.com |
| SyncSpaces, pinned tabs and settings sync across devices. | ✓ | ✓ | Spaces, Profiles, bookmarks, pinned tabs, URL Rules, settings, history between Macs; labelled experimental.phibrowser.com |
| Mobile appiPhone, iPad or Android app that shares spaces with desktop. | ✕ | ◐ | No mobile app; Phi Link reaches the assistant through your own Telegram bot only.phibrowser.com |
Extras
| Feature | Phi | Arc | Note |
|---|---|---|---|
| Built-in ad blockerAd and tracker blocking without installing an extension. | ◐ | ✓ | Ads, trackers and cookie banners can be blocked per Profile, but all three switches are off by default.phibrowser.com |
| Custom ShortcutsShortcut editorMost browser keyboard shortcuts can be remapped in Settings. | ✓ | ✓ | Settings → Shortcuts records custom keys or disables browser commands; overrides are saved per account and conflicts are flagged.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 | Phi | Arc | Note |
|---|---|---|---|
| EaselsA shareable canvas of live page captures, notes and drawings. | ✕ | ◐ | No canvas or board code at 28df0d0 and none in Canary 970; the item model has no board or note-canvas type.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. | ◐ | ✓ | File menu 'Export Bookmarks…' saves a Space's bookmarks and pinned tabs as an HTML file; no shareable link or shared Space.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. | ✕ | ✓ | Peek previews links only; no calendar, unread or live app-glance code, and tab corner badges show only chat and agent state.github.com |
| Developer modeA developer view that turns on by itself for localhost: full URL, quick DevTools and dev tools in reach. | ✕ | ✓ | The 'Developer mode' toggle only unlocks a Developer tab for agent (CDP) access and Bitwarden; no localhost mode or JSON viewer.github.com |
Extension support
Which extension formats and stores run, beyond the Chrome Web Store row above.
| Feature | Phi | Arc | Note |
|---|---|---|---|
| Manifest V2 extensionsThe older extension format Chrome removed in 2025. Needed for full uBlock Origin and other extensions that block requests. | ✕ | ✕ | Chromium 156 blocks MV2 with no flag; Canary 970 holds stock MV2 handler strings, no restore patch found.chromium.googlesource.com |
| Manifest V3 extensionsThe current extension format used by the Chrome Web Store (and supported by Firefox and Safari). | ✓ | ✓ | Chromium 156 loads MV3 (max supported 3); Phi installs Chrome Web Store extensions per Profile.chromium.googlesource.com |
| Firefox add-onsAdd-ons from addons.mozilla.org or .xpi files install and run. | ✕ | ✕ | Chromium-based: Firefox .xpi add-ons are not CRX packages, so its installer rejects them.chromium.googlesource.com |
| Safari extensionsSafari web extensions (the App Store extension apps Safari uses) install and run. | ✕ | ✕ | Safari extensions are app extensions that only Safari loads; Chromium 156 has no loader for them.developer.apple.com |