Meridian
Open-source Arc replacement with spaces, Arc import and a built-in MCP server, now a Chromium build for Mac.
Meridian is a free browser by one developer that copies Arc's workflow: spaces with their own profiles, favorites, pinned tabs and folders, a Today list that auto-archives, split view, Peek, a command bar, Little windows and Air Traffic Control. It imports an Arc sidebar and Arc's sign-ins on macOS. It is built around AI: a built-in Ask panel and an MCP server that lets Claude Code or other agents drive the browser. Since 0.5.0 it is a patched Chromium build (a WebUI-browser sidebar) instead of the earlier Electron app; 0.5.x ships for macOS Apple silicon only, and Windows and Linux builds exist only up to the Electron-era 0.4.x. The app is not notarized and is signed ad hoc.
71% Arc feature parity (yes = 1, partial = ½).
AI optional
Ask panel, chat and MCP server ship, but need your own API key, Ollama/LM Studio or agent CLI; agent access defaults to off. Marketed as AI-centric.
github.comNot counted in Arc parity: some people want AI, some avoid it.
None found
Privacy page: no account, server or telemetry; only filter-list downloads and a daily GitHub release check. No ads, wallet, feed or paid tier found.
github.comAds, crypto, paid upsells, news feeds, default-on telemetry, required accounts.
Organization
| Feature | Meridian | Arc | Note |
|---|---|---|---|
| Vertical sidebarTabs live in a vertical sidebar that is the main tab UI and can be hidden. | ✓ | ✓ | Chromium WebUI browser restyled: vertical sidebar on the left, page as a rounded card; ⌘S hides it.github.com |
| SpacesSeveral workspaces per window, each with its own pinned and open tabs, switched by swipe or shortcut. | ✓ | ✓ | Spaces with their own pinned items and Today tabs, each with colour and icon; switch by shortcut or swipe.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. | ✓ | ✓ | Right-click a space and pick a Profile (own cookies and logins); a profile can serve several spaces.github.com |
| Global favoritesPinned icons at the top of the sidebar shared by every Space (Zen calls them Essentials). | ✓ | ✓ | Favorites grid shared by every space of a profile; each profile has its own list, as in Arc.github.com |
| Pinned tabs & foldersPer-space pinned tabs that act like bookmarks, with nested folders. | ✓ | ✓ | Per-space pinned links that remember their home URL, plus folders.github.com |
| Auto-archive tabsUnpinned tabs close automatically after a set time and stay recoverable in an archive. | ✓ | ✓ | Unvisited Today tabs archive after 12 h by default (Settings changes it); Archive panel restores them.github.com |
| Space themesPer-space colour or gradient themes. | ✓ | ✓ | Edit Space Theme: each space has its own colour, gradient and icon.github.com |
Browsing
| Feature | Meridian | Arc | Note |
|---|---|---|---|
| Split ViewTwo or more tabs side by side in one window. | ◐ | ✓ | Chromium split tabs: two tabs side by side with a draggable divider; no third pane.github.com |
| Link previewOpen a link in an overlay without leaving the current page (Zen calls it Glance). | ◐ | ✓ | Peek card opens only for links from a pinned tab to another site; expand to a tab.github.com |
| Mini windowA small, chrome-less window for links opened from other apps or a quick search. | ✓ | ✓ | Links from other apps open in a Little window; Open in Meridian moves them to the main window.github.com |
| Command barA ⌘T palette that searches tabs, history, bookmarks and browser commands. | ◐ | ✓ | ⌘T/⌘L bar: open tabs (Switch to Tab), history, bookmarks and web search; no browser-command search found.github.com |
| Link routingRules that send links from other apps to a chosen space or profile. | ✓ | ✓ | Air Traffic Control: rules by domain or URL pattern pick where a link from another app opens.github.com |
| Site customizationPer-site custom CSS/JS, or zapping elements off a page. | ✕ | ✓ | README lists "No Boosts, Easels or Notes"; Boosts-style site tweaks are only on the roadmap.github.com |
| Auto picture-in-picturePlaying video pops out into picture-in-picture automatically when you switch tabs. | ✓ | ✓ | Browser-initiated automatic picture-in-picture is on by default; blockable per site.github.com |
Compatibility & migration
| Feature | Meridian | Arc | Note |
|---|---|---|---|
| Arc importImports Arc spaces, pinned tabs and folders. | ✓ | – | Imports Arc spaces, pins, folders, favorites and open tabs, plus Arc sign-in cookies after a keychain prompt.github.com |
| Chrome extensionsInstalls extensions from the Chrome Web Store. | ✓ | ✓ | Real Chromium: Web Store extensions install; Arc import lists your Arc extensions to add.github.com |
| DRM (Widevine)Netflix, Disney+, Spotify web and other DRM video/audio play. Chromium forks need a Google Widevine licence. | ? | ✓ | 0.5.13 bundle has no Widevine CDM and args.gn sets no Widevine option; playback not run. |
| PasskeysWebAuthn passkeys, Touch ID and the system/iCloud keychain. | ◐ | ✓ | 0.5.13 app is signed ad hoc with no keychain entitlement, so Touch ID/iCloud passkeys are unlikely.github.com |
| SyncSpaces, pinned tabs and settings sync across devices. | ✕ | ✓ | README: no sync yet; "sync between devices" is on the roadmap.github.com |
| Mobile appiPhone, iPad or Android app that shares spaces with desktop. | ✕ | ◐ | Desktop only; the 0.5.13 release ships only a macOS Apple-silicon build.github.com |
Extras
| Feature | Meridian | Arc | Note |
|---|---|---|---|
| Built-in ad blockerAd and tracker blocking without installing an extension. | ✓ | ✓ | EasyList and EasyPrivacy filter ads and trackers on every site, no extension; toggle in Settings.github.com |
Extension support
Which extension formats and stores run, beyond the Chrome Web Store row above. Not counted in Arc parity.
| Feature | Meridian | Arc | Note |
|---|---|---|---|
| Manifest V2 extensionsThe older extension format Chrome removed in 2025. Needed for full uBlock Origin and other extensions that block requests. | ✕ | ✕ | Stock Chromium 158 disables MV2 with no flag or policy; no Meridian patch restores it.github.com |
| Manifest V3 extensionsThe current extension format used by the Chrome Web Store (and supported by Firefox and Safari). | ◐ | ✓ | Experimental: MV3 background and content scripts load, but toolbar popups don't work yet.github.com |
| Firefox add-onsAdd-ons from addons.mozilla.org or .xpi files install and run. | ✕ | ✕ | Chromium engine loads Chrome-format extensions only; Firefox add-ons (.xpi) aren't supported.github.com |
| Safari extensionsSafari web extensions (the App Store extension apps Safari uses) install and run. | ✕ | ✕ | Chromium engine loads Chrome-format extensions only; Safari extension apps can't run.github.com |