Shiira
Free, open-source Electron browser with Arc-style Spaces, Peek, split view, Arc import and an ad blocker.
Shiira is an Electron browser written by one developer (skonester) as a homage to the old Shiira browser for Mac OS X, rebuilt around an Arc-style sidebar. It has Spaces with their own pinned and Today tabs, shared favorites, nested pinned folders, an archive for idle tabs, two-pane split view, Peek, a command bar, tab sleep, Arc import and a Ghostery-based ad blocker, plays YouTube through its own stream player (Litube-style, with a button to fall back to YouTube's player; Shorts use YouTube's own), and it installs Chrome Web Store extensions, with only part of the extension APIs. All Spaces share one session, so there are no Profiles, Little Arc, Boosts, sync or mobile app. The Mac build is Apple Silicon only, ad-hoc signed and not notarized. The project says to use it as a secondary browser.
Built-in AI
AI optional
Optional Scira AI search, off until you pick it: with your API key it answers inline, without one (0.3.8) it opens scira.ai in the tab. No bundled assistant.
github.comBloat check
None found
No analytics, telemetry or account code found in the source. Update checks against GitHub Releases are on by default and can be switched off.
github.comAds, crypto, paid upsells, news feeds, default-on telemetry, required accounts.
Organization
| Feature | Shiira | Arc | Note |
|---|---|---|---|
| SidebarVertical sidebarTabs live in a vertical sidebar that is the main tab UI and can be hidden. | ✓ | ✓ | Vertical sidebar is the default layout; Ctrl+S hides it. A classic top tab strip is an optional setting.github.com |
| SpacesSeveral workspaces per window, each with its own pinned and open tabs, switched by swipe or shortcut. | ✓ | ✓ | Spaces with their own name, emoji, colour, pinned and Today tabs; switch with Alt+1 to 9 or Ctrl+Alt+Left/Right.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. | ✕ | ✓ | All Spaces share one persist:main session; the project lists isolated profiles linked to Spaces as a gap.github.com |
| FavoritesGlobal favoritesPinned icons at the top of the sidebar shared by every Space (Zen calls them Essentials). | ✓ | ✓ | Favorites sit above the Spaces and are shared by every Space; any tab can be added from its menu.github.com |
| Pinned TabsPinned tabs & foldersPer-space pinned tabs that act like bookmarks, with nested folders. | ✓ | ✓ | Per-Space pinned tabs with nested folders, drag and drop, and reset to the saved URL.github.com |
| Live foldersSidebar folders that fill and refresh themselves from an outside source, such as GitHub pull requests or an RSS feed. | ✕ | ✓ | Folders are manual only; the project lists no feed- or source-backed folders among its features.github.com |
| ArchiveAuto-archive tabsUnpinned tabs close automatically after a set time and stay recoverable in an archive. | ✓ | ✓ | Today tabs idle for 12 h by default move to an Archive you can search and restore; the time is a setting.github.com |
| Theme pickerSpace themesPer-space colour or gradient themes. | ✓ | ✓ | Each Space picks one of 8 colours or a custom colour that tints its sidebar; app themes are separate.github.com |
Browsing
| Feature | Shiira | Arc | Note |
|---|---|---|---|
| Split ViewTwo or more tabs side by side in one window. | ◐ | ✓ | Only two side-by-side tabs with a draggable divider; the project lists 3 to 4 pane layouts as a gap.github.com |
| PeekLink previewOpen a link in an overlay without leaving the current page (Zen calls it Glance). | ✓ | ✓ | Shift+click, or a link to another site from a pinned tab, opens an overlay that can become a tab or split.github.com |
| Little ArcMini windowA small, chrome-less window for links opened from other apps or a quick search. | ✕ | ✓ | The project lists a temporary window for external links (Little Arc) as a gap.github.com |
| Command barA ⌘T palette that searches tabs, history, bookmarks and browser commands. | ◐ | ✓ | Ctrl+T palette finds open tabs, archived tabs, Spaces, history and its commands; bookmarks are not searched.github.com |
| Air Traffic ControlLink routingRules that send links from other apps to a chosen space or profile. | ✕ | ✓ | No routing rules for links from other apps; the project lists external-link handling as a gap.github.com |
| BoostsSite customizationPer-site custom CSS/JS, or zapping elements off a page. | ✕ | ✓ | The project says Boosts are not implemented.github.com |
| Auto PiPAuto picture-in-picturePlaying video pops out into picture-in-picture automatically when you switch tabs. | ✕ | ✓ | No picture-in-picture handling in the renderer; tab audio events only show a speaker icon.github.com |
| Mini playerMedia still playing in a tab you left keeps play/pause controls in the sidebar. | ◐ | ✓ | Audible tabs show a speaker icon that mutes them; there is no play/pause or now-playing control.github.com |
| Tab SwitcherRecent-tab switcherCtrl+Tab jumps back to the tab you used last and cycles in recently used order. | ✕ | ✓ | Ctrl+Tab cycles tabs in sidebar order, not most-recently-used order.github.com |
| Super CopyClean link copyA shortcut (⌘⇧C) copies the page URL with tracking parameters removed. | ◐ | ✓ | Ctrl+Shift+C copies the page address as is, with tracking parameters kept.github.com |
| CaptureScreenshotsBuilt-in capture of a chosen area or element, and of the full page. | ✕ | ✓ | No page or area screenshot command in the source; only images on a page can be copied or saved from the context menu.github.com |
Compatibility & migration
| Feature | Shiira | Arc | Note |
|---|---|---|---|
| Arc importImports Arc spaces, pinned tabs and folders. | ✓ | – | Imports Arc Spaces, nested pinned tabs and folders, favorites, archive and optional Today tabs and history from a local Arc install or copied folder.github.com |
| Chrome extensionsInstalls extensions from the Chrome Web Store. | ◐ | ✓ | Installs Chrome Web Store extensions via electron-chrome-extensions, but Electron supports only a subset of the Chrome extension APIs.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. | ◐ | ✓ | castLabs Electron installs the Widevine CDM in the background, but the release workflow has no castLabs VMP signing step, which services like Netflix need.github.com |
| PasskeysWebAuthn passkeys, Touch ID and the system/iCloud keychain. | ◐ | ✓ | Ad-hoc signed DMG with no entitlements, so no system keychain passkeys; WebAuthn falls back to Chromium (security keys). Not tested.github.com |
| SyncSpaces, pinned tabs and settings sync across devices. | ✕ | ✓ | The project says cross-device sync is not implemented.github.com |
| Mobile appiPhone, iPad or Android app that shares spaces with desktop. | ✕ | ◐ | Builds exist for Windows, macOS and Linux only.github.com |
Extras
| Feature | Shiira | Arc | Note |
|---|---|---|---|
| Built-in ad blockerAd and tracker blocking without installing an extension. | ✓ | ✓ | Ghostery-based ad and tracker blocking, on by default. YouTube watch pages skip cosmetic rules and use Shiira's own player; Shorts (0.3.9) use YouTube's player, unfiltered.github.com |
| Custom ShortcutsShortcut editorMost browser keyboard shortcuts can be remapped in Settings. | ✕ | ✓ | Shortcuts are hard-coded; Settings only lists a few of them.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 | Shiira | Arc | Note |
|---|---|---|---|
| EaselsA shareable canvas of live page captures, notes and drawings. | ✕ | ◐ | The project says Easels are not implemented.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. | ✕ | ✓ | No export or link sharing of Spaces or folders; the project lists no such feature.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 hover previews, unread badges or calendar widgets on pinned tabs or favorites.github.com |
| Developer modeA developer view that turns on by itself for localhost: full URL, quick DevTools and dev tools in reach. | ✕ | ✓ | Only the standard developer tools shortcut (Ctrl+Shift+I); no localhost-specific developer mode.github.com |
Extension support
Which extension formats and stores run, beyond the Chrome Web Store row above.
| Feature | Shiira | Arc | Note |
|---|---|---|---|
| Manifest V2 extensionsThe older extension format Chrome removed in 2025. Needed for full uBlock Origin and other extensions that block requests. | ? | ✕ | Not documented: the README only names Manifest V3 extensions. |
| Manifest V3 extensionsThe current extension format used by the Chrome Web Store (and supported by Firefox and Safari). | ◐ | ✓ | Manifest V3 Chrome Web Store extensions install, but Electron implements only a subset of the extension APIs.github.com |
| Firefox add-onsAdd-ons from addons.mozilla.org or .xpi files install and run. | – | ✕ | Runs only Chrome Web Store extensions.github.com |
| Safari extensionsSafari web extensions (the App Store extension apps Safari uses) install and run. | – | ✕ | Runs only Chrome Web Store extensions.github.com |