Flow
Open-source Electron browser with Arc/Zen-style sidebar, profiles with spaces, command palette and Widevine.
Flow is an open-source desktop browser built on Electron (Chromium) by Multibox Labs, mainly developed by one maintainer. It organizes tabs into spaces that each belong to a profile, with a sidebar, a command palette and Chrome Web Store extension support. Its design is inspired by Arc and Zen. Last release is v0.12.1 (April 2026) and the last commit is from May 2026. It is labelled Beta on its website and is still pre-1.0.
50% Arc feature parity (yes = 1, partial = ½).
Built-in AI
No AI
No built-in AI; an AI agent exists only as an open draft PR (#228).
github.comNot counted in Arc parity: some people want AI, some avoid it.
Bloat check
1 thing you didn't ask for
- Telemetry on by defaultPostHog starts on launch with an anonymous ID: sends an app-started event and auto-captured errors; no opt-out setting found.github.com
No ads, wallet, feed, upsell or account code found in the source.
Ads, crypto, paid upsells, news feeds, default-on telemetry, required accounts.
Organization
| Feature | Flow | Arc | Note |
|---|---|---|---|
| Vertical sidebarTabs live in a vertical sidebar that is the main tab UI and can be hidden. | ✓ | ✓ | Sidebar with floating (auto-hide) mode; can sit on the left or right side.github.com |
| SpacesSeveral workspaces per window, each with its own pinned and open tabs, switched by swipe or shortcut. | ◐ | ✓ | Spaces have their own open tabs, but pinned tabs belong to the profile, not to each space.github.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 belongs to one profile chosen at creation; a profile can hold several spaces.github.com |
| Global favoritesPinned icons at the top of the sidebar shared by every Space (Zen calls them Essentials). | ◐ | ✓ | Pinned tabs are shared by a profile's spaces, not across profiles; 'Favorites' is still a roadmap item.flow-browser.com |
| Pinned tabs & foldersPer-space pinned tabs that act like bookmarks, with nested folders. | ◐ | ✓ | Pinned tabs added in v0.11.0 as a flat per-profile list; no folders found.github.com |
| Auto-archive tabsUnpinned tabs close automatically after a set time and stay recoverable in an archive. | ◐ | ✓ | Idle tabs auto-close after 12h-30d (setting); recovery is a session-only list of 10 recently closed tabs.github.com |
| Space themesPer-space colour or gradient themes. | ✓ | ✓ | Each space has its own background gradient colours and icon.github.com |
Browsing
| Feature | Flow | Arc | Note |
|---|---|---|---|
| Split ViewTwo or more tabs side by side in one window. | ✕ | ✓ | Split tab group class in source is an unimplemented TODO.github.com |
| Link previewOpen a link in an overlay without leaving the current page (Zen calls it Glance). | ✕ | ✓ | Glance (peek) code exists but the GLANCE_ENABLED flag is false in source.github.com |
| Mini windowA small, chrome-less window for links opened from other apps or a quick search. | ◐ | ✓ | Popup windows exist; external links open as a tab in the focused window.github.com |
| Command barA ⌘T palette that searches tabs, history, bookmarks and browser commands. | ✓ | ✓ | Palette covers open tabs, history, commands, search suggestions and bangs; no bookmarks feature.github.com |
| Link routingRules that send links from other apps to a chosen space or profile. | ✕ | ✓ | External links just open as a new tab in the focused window; no rules.github.com |
| Site customizationPer-site custom CSS/JS, or zapping elements off a page. | ✕ | ✓ | No per-site CSS/JS or element zapping in source; only extensions can do this.github.com |
| Auto picture-in-picturePlaying video pops out into picture-in-picture automatically when you switch tabs. | ✓ | ✓ | Playing video enters PiP automatically when its tab is hidden; no setting found.github.com |
Compatibility & migration
| Feature | Flow | Arc | Note |
|---|---|---|---|
| Arc importImports Arc spaces, pinned tabs and folders. | ✕ | – | No import feature or Arc data reader in source; settings have no import section.github.com |
| Chrome extensionsInstalls extensions from the Chrome Web Store. | ✓ | ✓ | Installs from the Chrome Web Store; site labels it Experimental and some extension APIs are incomplete.github.com |
| DRM (Widevine)Netflix, Disney+, Spotify web and other DRM video/audio play. Chromium forks need a Google Widevine licence. | ✓ | ✓ | castLabs Electron (Widevine); build VMP-signs macOS (afterPack) and Windows (afterSign), not Linux.github.com |
| PasskeysWebAuthn passkeys, Touch ID and the system/iCloud keychain. | ◐ | ✓ | Native passkeys/Touch ID on macOS only (since v0.8.6); Windows/Linux not documented.github.com |
| SyncSpaces, pinned tabs and settings sync across devices. | ✕ | ✓ | No backend or accounts; only tab sync across windows on one device.github.com |
| Mobile appiPhone, iPad or Android app that shares spaces with desktop. | ✕ | ◐ | Desktop builds only (macOS, Windows, Linux, Flatpak).github.com |
Extras
| Feature | Flow | Arc | Note |
|---|---|---|---|
| Built-in ad blockerAd and tracker blocking without installing an extension. | ◐ | ✓ | Built-in Ghostery-based blocker, but it is Disabled by default.github.com |
Extension support
Which extension formats and stores run, beyond the Chrome Web Store row above. Not counted in Arc parity.
| Feature | Flow | Arc | Note |
|---|---|---|---|
| Manifest V2 extensionsThe older extension format Chrome removed in 2025. Needed for full uBlock Origin and other extensions that block requests. | ◐ | ✕ | Only behind the off-by-default "Re-enable Manifest V2 extensions [UNSTABLE]" setting.github.com |
| Manifest V3 extensionsThe current extension format used by the Chrome Web Store (and supported by Firefox and Safari). | ◐ | ✓ | Installs, but Electron lists no declarativeNetRequest, so MV3 content blockers cannot block.github.com |
| Firefox add-onsAdd-ons from addons.mozilla.org or .xpi files install and run. | ✕ | ✕ | Chrome-format only (Chrome Web Store installs); no Firefox add-on install path.github.com |
| Safari extensionsSafari web extensions (the App Store extension apps Safari uses) install and run. | ✕ | ✕ | Chrome-format extensions only; Electron has no Safari extension host.github.com |