Install

Nothing at all for the browser; one build for the command line

The browser version

There is nothing to install.

https://googlefonts.github.io/slice-web/app/

It is a static page and a WebAssembly module. Any current version of Firefox, Chrome, Edge or Safari runs it. Your font is read, sliced and returned by the browser itself, so there is no account, no upload and no server-side component — you can load the page, go offline, and slice a font with the network disconnected.

If you would rather host it yourself, build it and copy the directory anywhere that serves static files:

git clone https://github.com/googlefonts/slice-web
cd slice-web
rustup target add wasm32-unknown-unknown
cargo install wasm-pack
./build.sh
python3 -m http.server --directory dist 8080

The only requirement of the host is that it serves .wasm with the application/wasm content type, which every static host does by default.

The command line

slice is a single binary with no runtime dependencies — no Python, no fontTools, no system libraries beyond libc.

git clone https://github.com/googlefonts/slice-web
cd slice-web
cargo build --release -p slice-cli

The binary lands at target/release/slice. Copy it onto your PATH:

install -m755 target/release/slice ~/.local/bin/slice

Needs a Rust toolchain, which you can get from rustup.rs. Any stable Rust from 1.85 onwards will do; that floor comes from the read-fonts dependency rather than from this code.

Linux, macOS, Windows

The same two commands on all three. There is nothing platform-specific in the engine, and no code signing or notarisation step, because there is no desktop bundle to sign — this is where the browser version earns its keep relative to the original, which needs a per-platform installer, an Apple Developer certificate and a notarisation round-trip for every macOS release.

On Windows use PowerShell and cargo build --release -p slice-cli; the binary is target\release\slice.exe.

Verifying a build

cargo test --workspace       # 192 tests
tests/suite/run.py           # the 298-case conformance corpus, both implementations

The corpus bootstraps its own virtual environment with PyQt5 and fontTools on first run, because it drives the original Slice as a library to compare against. That is only needed for the corpus; nothing in Slice itself uses Python.

What about a desktop app?

There isn’t one, and that is deliberate. The original ships a .dmg and a .exe because a PyQt5 application has to; a page that works on every platform at one URL does not. If you want something that behaves like an installed app, every current browser will install this one as a standalone window — in Chrome and Edge, Install page as app from the address bar.