Crest brings Arc-style browsing to Mac, iPad and iPhone as open source

Crest, a new open-source web browser for Mac, iPad and iPhone, has launched in early access. It is explicitly pitched at former Arc users: the project's tagline is "the browser for life after Arc," and according to Crest's website the app ships with a feature-by-feature guide showing how Arc capabilities translate into their Crest equivalents. The browser is released under the MPL 2.0 license, its code is openly available, and the project is careful to note that it is not affiliated with Arc.

An Arc feature map, with new names

Most of Arc's signature ideas reappear in Crest. Spaces keep their name (Arc's Profiles are folded into them), and the sidebar, Peek previews and Split View carry over unchanged. Other features have been renamed: Arc's Favorites become Pinned sites, Pinned Tabs become Saved tabs, the Command Bar becomes a command palette, and Air Traffic Control is reborn as Link Routing. Little Arc, the lightweight quick-view window, returns as Quick Window.

The mapping extends across the rest of the product. Auto Archive becomes Space cleanup, the Recent Tab Switcher becomes Most Recent Tab, and Arc Sync is replaced by iCloud synchronisation for Spaces, tabs and folders. Incognito mode has become Private Spaces, which retain nothing and can optionally be locked behind Face ID or Touch ID. Extensions are installed per Space from the Chrome Web Store, site permissions are remembered per site and per Space, and keyboard shortcuts are rebindable.

Two engines on the Mac, iCloud everywhere

The most unusual technical decision is dual-engine support on the Mac: Crest ships with Chromium as its primary engine but can also render sites with WebKit on a per-site basis. That combination gives users Chrome extension compatibility alongside an Apple-native engine option. Downloads can pause and resume under Chromium, and developer tools including viewports, a console and network inspection are available on the Mac.

Much of the rest of the feature set leans on Apple's platforms. Crest's password manager stores credentials in the Keychain and matches them per Space, whole-page translation runs on device, and content blocking is available through uBlock Origin Lite or a built-in list. Reader mode works on iPhone, iPad and WebKit-rendered pages. On the smaller screens, pages run full screen with the sidebar available by swipe. There are also quality-of-life touches such as Keep Loaded, which prevents a page from being evicted from memory, and configurable space cleanup that archives tabs after a period ranging from 12 hours to 30 days.

Moving in from Arc, or elsewhere

For people coming from Arc, Crest imports Spaces, tabs, folders, colors, icons and passwords. Migration happens on the Mac and includes a review step, letting users inspect each Space before committing to the move. Imports are also supported from Zen (Spaces, Essentials, pinned tabs, folders, colors), Chrome (profiles, bookmarks, open tabs, passwords), Safari (bookmarks, windows, open tabs) and Firefox (windows, open tabs, pinned tabs).

Early access, with caveats

Crest is available now in early access. The project states plainly that its security has not been independently audited, which is a meaningful caveat for anyone considering it as a daily driver, since browsers handle passwords, cookies and session tokens. The combination of an early build and no third-party audit argues for treating it as promising rather than proven.

Why it matters

Arc built a devoted following around its spatial, opinionated take on browsing, and its discontinuation left those users without an obvious successor. Crest is the most direct attempt yet to fill that gap on Apple platforms: it reproduces Arc's feature set almost one-for-one, keeps user data inside Apple's ecosystem through iCloud and the Keychain rather than a proprietary sync service, and releases its source under MPL 2.0 so the project can outlive any single company's roadmap. The open-source approach also answers one of the loudest complaints of the Arc era — people who invested heavily in their setups had nowhere to take them once development stopped. Crest still has to establish a track record on stability, performance and security. But for the Arc diaspora on Mac, iPad and iPhone, it is a credible option, and one whose development anyone can now inspect.