A web browser written from scratch, for Windows, Linux, and macOS. It is early, it is public, and it measures itself on public yardsticks, never vibes.
The bar. Every feature is to be at least what the shipping browsers offer, and better where it can be. Where Sashfold is short of that today, it is because the work is not done — never because it was decided against.
The pledge. Whatever can be written from scratch is: the code that ships in a Sashfold binary is written in this repository, and the binary links only the operating system's interfaces and the language runtime, which tools/pledge-check.sh enforces in CI. Where a thing cannot be written here — a graphics card's driver, the operating system's own TLS on Windows and macOS — Sashfold uses what the platform provides, as every browser does. The pledge is how Sashfold is built; it is never a reason for a feature to fall short of the bar.
No telemetry, no sponsored tiles, no default-search auction, no account, no cloud AI. The boundary, drawn exactly: The Pledge.
- Browsing the live web over HTTPS — its own TLS on Linux, SChannel on Windows (Networking).
- The complete WHATWG HTML parser (Parsing).
- CSS — the cascade, flexbox, grid, tables,
@font-face(Styling, Layout). - Its own text rasterizer and image decoders (Painting and text).
- A JavaScript engine with the DOM, events, timers, modules and promises (Scripting).
- A shell — tabs, history, containers, themes, devtools, reader mode (The shell).
What is still short of the bar is listed, not hidden: Not written yet. The design is on the wiki too: Architecture, Why C++, Security defaults.
| Yardstick | Score |
|---|---|
| html5lib tokenizer / tree construction | 7032 / 7032 and 1784 / 1784 (100%) |
| WPT URL parsing | 893 / 893 (100%) |
| Unicode bidi | 91,707 / 91,707 and 770,241 / 770,241 (100%) |
| Unicode line breaking | 16,672 / 16,672 (100%) |
| WPT CSS reference tests | 10362 / 15682 (66.1%) — sashfold.com/wpt.html |
| WPT testharness tests | 195299 / 242189 (80.6%) — sashfold.com/wpt-harness.html |
| test262 | 41845 / 45367 (92.2%) — sashfold.com/test262.html |
| The Sashfold 100 | sashfold.com/sashfold100 · the Linux render |
Every score is enforced in CI: a test that stops passing fails the build. How each is scored is on Measurements.
Requires CMake ≥ 3.24, Ninja, and a C++23 compiler (gcc ≥ 13 or clang ≥ 16). Nothing else.
cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
cmake --build build
ctest --test-dir build --output-on-failure
The compilers and tools by distribution:
sudo pacman -S --needed base-devel cmake ninja # Arch
sudo apt install build-essential cmake ninja-build # Debian 13 / Ubuntu 24.04 or later (gcc ≥ 13)
sudo apk add build-base cmake ninja linux-headers # Alpine (musl)
On musl the same steps build and run it; CI builds and tests every change on Alpine.
bash tools/buildall.sh runs the gcc and clang lanes plus the pledge and egress checks.
Downloads are on the releases page: a Windows x64 zip, a Linux x64 tarball and a Debian package, or sashfold-bin on the AUR.
sashfold # the browser window (Windows and Linux)
sashfold https://example.org/ # ...opened on a page
sashfold --render page.html -o out.png # render a page headlessly
sashfold --bench page.html # time parse, style, layout, paint
sashfold --script tests/shell/live.script # drive the shell from a text file
Every mode and flag is on Running Sashfold; the window's look comes from a theme file (Themes).