Ladybird Review

Ladybird shares no code with the other major engines. The architecture is multi-process: a main UI process, several WebContent renderer processes (each tab gets its own sandboxed renderer), an ImageDecoder process, and a RequestServer process, so image decoding and networking run out of process for robustness against malicious content. Core libraries, largely inherited from SerenityOS, include LibWeb for rendering, LibJS for JavaScript, LibWasm for WebAssembly, LibHTTP, LibGfx for graphics and image formats, LibMedia for audio and video, LibCore, and LibIPC. OpenAlternative notes work on an inline PDF viewer, browsing history, HTTP caching, media streaming, CSS anchor positioning, off-thread JavaScript compilation, a new regular-expression engine, and gradual rewrites of subsystems in Rust, and says an alpha release for Linux and macOS is targeted for 2026.

There is no consumer installer: you build from source following Documentation/BuildInstructionsLadybird.md. The build needs a C++23-capable compiler (CI uses gcc-14 and clang-21), a Rust toolchain installed through rustup, CMake 3.30 or newer, nasm, Ninja, and pkg-config, plus Qt 6.10 or newer with private development packages for the UI on every platform except Android. Distribution Qt versions can be too old: Debian 13 ships Qt 6.8, which fails to configure, so you install a newer Qt and point the build at it with CMAKE_PREFIX_PATH. On macOS you need Xcode 15 or Homebrew clang and a long list of Homebrew packages, and on Windows WSL2 is the supported path (WSL1 has known issues, MinGW and MSYS2 are not supported, and Clang-CL is experimental). Android builds go through the Android Studio guide or Gradle 8.0.0 or newer. The commands are ./Meta/ladybird.py run for a release build and run, BUILD_PRESET=Debug for debug builds, and -DLAGOM_LINK_POOL_SIZE=2 to limit parallel links on low-memory systems. The docs state no disk or RAM requirements. A known gotcha: the error Unable to find a build program corresponding to Ninja usually means a vcpkg dependency failed, so check vcpkg-manifest-install.log in the build directory, and building with the Xcode project generated by CMake is not supported.

As a daily browser it is not ready: expect missing features, site-compatibility gaps, and rough edges, which the project's own pre-alpha label warns about. It is interesting to watch and to build, and it is a useful reference for how a modern engine can be organized around process isolation. The project's website was unreachable when we tried to read it, so this section reflects the README, build documentation, and OpenAlternative; we did not build or browse with Ladybird.

• Independent engine with no Blink, WebKit, or Gecko code
• Multi-process architecture with a sandboxed renderer per tab
• Out-of-process image decoding and networking
• Custom libraries for rendering, JavaScript, WebAssembly, graphics, and media
• Qt-based UI on desktop platforms, plus an Android UI
• Progress on PDF viewing, HTTP caching, media streaming, and modern CSS
• Gradual Rust rewrites of some subsystems

• A genuinely new engine, which is rare and valuable for web diversity
• Non-profit governance with no search deals, data collection, or advertising
• BSD-2-Clause license, and about 66,500 stars with commits within hours of this review
• Architecture designed for security and process isolation

• Pre-alpha and developer-only, per the README
• No official daily-driver release yet, with an alpha for Linux and macOS only targeted for 2026
• Building it is non-trivial: it needs Qt 6.10 or newer, CMake 3.30 or newer, a Rust toolchain, and a modern C++ compiler, and common distribution packages are too old
• Windows support goes through WSL2, and compatibility with the real-world web is incomplete
• No sync, extension ecosystem, or polish comparable to mature browsers, and funding depends on donations and sponsorships

Ladybird is free and open source under BSD-2-Clause. It is funded through donations and sponsorships on Open Collective rather than advertising or search deals.

Chrome, Brave, Comet, and many others are built on Chromium (Blink), Firefox is on Gecko, and Safari is on WebKit, so most browsers share one of three engines. Ladybird is the only serious project building a fourth independent engine, which is why it matters even before it is usable. Today, Firefox is the independent-engine option you can actually use daily, and Ladybird is a long-term bet.

• Developers who want to follow or contribute to a new browser engine
• People interested in browser architecture and web standards
• Supporters of an independent, non-profit web platform

• Anyone who needs a browser for everyday use
• Teams that require extension support or enterprise management
• Users who need compatibility with every modern site today