alacritty/README.md

Alacritty

Alacritty is the fastest terminal emulator in existence. Using the GPU for rendering enables optimizations that simply aren't possible in other emulators. Alacritty currently supports macOS and Linux, and Windows support is planned before the 1.0 release.

About

Alacritty is focused on simplicity and performance. The performance goal means it should be faster than any other terminal emulator available. The simplicity goal means that it doesn't have many features like tabs or scroll back as in other terminals. Instead, it is expected that users of Alacritty make use of a terminal multiplexer such as tmux.

This initial release should be considered to be pre-alpha software--it will have issues. Once Alacritty reaches an alpha level of readiness, precompiled binaries will be provided for supported operating systems.

Blog Posts

• Announcing Alacritty, a GPU-Accelerated Terminal Emulator January 6, 2017

Installation

The only supported installation method at this time is from source. Proper installers will be added prior to the 1.0 release of Alacritty. This section will walk you through how to build from source on both macOS and Ubuntu.

Prerequisites

1. Install rustup.rs

2. Clone the source code:

   git clone https://github.com/jwilm/alacritty
   cd alacritty
   

3. Make sure you have the right Rust compiler installed. Alacritty requires nightly Rust. Run

   rustup override set nightly
   

   If you run into problems, you can try a known-good version of the compiler by running

   rustup override set $(cat rustc-version)
   

Additional Linux Prerequisites

Ubuntu

On Ubuntu, you need a few extra libraries to build Alacritty. Here's an apt command that should install all of them. If something is still found to be missing, please open an issue.

apt-get install cmake libfreetype6-dev libfontconfig1-dev xclip

Arch Linux

On Arch Linux, you need a few extra libraries to build Alacritty. Here's a pacman command that should install all of them. If something is still found to be missing, please open an issue.

pacman -S cmake freetype2 fontconfig xclip

Fedora

On Fedora, you need a few extra libraries to build Alacritty. Here's a dnf command that should install all of them. If something is still found to be missing, please open an issue.

dnf install freetype-devel fontconfig-devel xclip

openSUSE

On openSUSE, you need a few extra libraries to build Alacritty. Here's a zypper command that should install all of them. If something is still found to be missing, please open an issue.

zypper install freetype-devel fontconfig-devel xclip

Other

If you build Alacritty on another Linux distribution, we would love some help filling in this section of the README.

Building

Once all the prerequisites are installed, compiling Alacritty should be easy:

cargo build --release

If all goes well, this should place a binary at target/release/alacritty. BEFORE YOU RUN IT: Install the config file as described below; otherwise, many things (such as arrow keys) would not work. If you're on macOS, you'll need to change the monospace font family to something like Menlo.

Desktop Entry

Many linux distributions support desktop entries for adding applications to system menus. To install the desktop entry for Alacritty, run

sudo cp target/release/alacritty /usr/local/bin # or anywhere else in $PATH
cp Alacritty.desktop ~/.local/share/applications

Configuration

Although it's possible the default configuration would work on your system, you'll probably end up wanting to customize it anyhow. There is an alacritty.yml at the git repository root. Copy this to either $HOME/.alacritty.yml or $XDG_CONFIG_HOME/alacritty.yml and run Alacritty.

Many configuration options will take effect immediately upon saving changes to the config file. The only exception is the font and dpi section which requires Alacritty to be restarted. For further explanation of the config file, please consult the comments in the default config file.

Issues (known, unknown, feature requests, etc)

If you run into a problem with Alacritty, please file an issue. If you've got a feature request, feel free to ask about it. Keep in mind that Alacritty is very much not looking to be a feature-rich terminal emulator with all sorts of bells and widgets. It's primarily a cross-platform, blazing fast tmux renderer that Just Works.

FAQ

• Is it really the fastest terminal emulator? In the terminals I've benchmarked against, alacritty is either faster, WAY faster, or at least neutral. There are no benchmarks in which I've found Alacritty to be slower.
• It's not fast! Why? There's a known bug affecting some versions of Mesa/libxcb where calls to glClear take an insanely long time. If it's not that, there's probably another bug. I'd be happy to look at the issue if you can provide some profiling information (wall time and otherwise).
• macOS + tmux + vim is slow! I thought this was supposed to be fast! This appears to be an issue outside of terminal emulators; either macOS has an IPC performance issue, or either tmux or vim (or both) have a bug. This same issue can be seen in iTerm2 and Terminal.app. I've found that if tmux is running on another machine which is connected to Alacritty via SSH, this issue disappears. Actual throughput and rendering performance are still better in Alacritty.
• Is wayland supported? Not yet. Alacritty is currently on a fork of glutin that needs some updates to work with Wayland. To stop glutin from detecting Wayland (e.g. for use on XWayland) launch Alacritty like this: env WAYLAND_DISPLAY= alacritty
• When will Windows support be available? When someone has time to work on it. Contributors would be welcomed :).
• My arrow keys don't work It sounds like you deleted some key bindings from your config file. Please reference the default config file to restore them.

License

Alacritty is released under the Apache License, Version 2.0.