Alacritty – GPU-Accelerated Terminal Emulator

Experience Blazing Fast Terminal Performance with Alacritty

Alacritty positions itself as the fastest terminal emulator in existence, leveraging GPU acceleration through OpenGL to achieve rendering performance that traditional CPU-bound terminals cannot match. This cross-platform terminal emulator, written in Rust, has gained significant popularity among developers and power users who demand maximum responsiveness from their terminal applications.

The project’s philosophy embraces simplicity and performance above feature accumulation. Rather than including built-in tabs, splits, or graphical configuration tools, Alacritty focuses on being an exceptionally fast, reliable terminal that integrates with external tools like tmux for additional functionality. This Unix-philosophy approach results in a lean, focused application that excels at its core purpose.

Installation

Linux Installation

Ubuntu/Debian:

sudo add-apt-repository ppa:aslatter/ppa
sudo apt update
sudo apt install alacritty

Fedora:

sudo dnf install alacritty

Arch Linux:

sudo pacman -S alacritty

From Source (Cargo):

cargo install alacritty

macOS Installation

brew install --cask alacritty

Windows Installation

choco install alacritty
# or
scoop install alacritty
# or
winget install Alacritty.Alacritty

Configuration

Configuration File Location

Alacritty uses TOML configuration (previously YAML):

# Linux/macOS
~/.config/alacritty/alacritty.toml

# Windows
%APPDATA%\alacritty\alacritty.toml

Create default configuration:

mkdir -p ~/.config/alacritty
touch ~/.config/alacritty/alacritty.toml

Basic Configuration

# alacritty.toml

[window]
opacity = 0.95
decorations = "full"
startup_mode = "Windowed"
title = "Alacritty"
dynamic_title = true

[window.dimensions]
columns = 120
lines = 40

[window.padding]
x = 10
y = 10

[scrolling]
history = 10000
multiplier = 3

[font]
size = 12.0

[font.normal]
family = "JetBrains Mono"
style = "Regular"

[font.bold]
family = "JetBrains Mono"
style = "Bold"

[font.italic]
family = "JetBrains Mono"
style = "Italic"

Color Schemes

Example Dracula theme:

[colors.primary]
background = "#282a36"
foreground = "#f8f8f2"

[colors.cursor]
text = "#282a36"
cursor = "#f8f8f2"

[colors.normal]
black = "#000000"
red = "#ff5555"
green = "#50fa7b"
yellow = "#f1fa8c"
blue = "#bd93f9"
magenta = "#ff79c6"
cyan = "#8be9fd"
white = "#bfbfbf"

[colors.bright]
black = "#4d4d4d"
red = "#ff6e67"
green = "#5af78e"
yellow = "#f4f99d"
blue = "#caa9fa"
magenta = "#ff92d0"
cyan = "#9aedfe"
white = "#e6e6e6"

Key Bindings

Custom key bindings:

[[keyboard.bindings]]
key = "V"
mods = "Control|Shift"
action = "Paste"

[[keyboard.bindings]]
key = "C"
mods = "Control|Shift"
action = "Copy"

[[keyboard.bindings]]
key = "N"
mods = "Control|Shift"
action = "SpawnNewInstance"

[[keyboard.bindings]]
key = "Plus"
mods = "Control"
action = "IncreaseFontSize"

[[keyboard.bindings]]
key = "Minus"
mods = "Control"
action = "DecreaseFontSize"

[[keyboard.bindings]]
key = "Key0"
mods = "Control"
action = "ResetFontSize"

Shell Integration

Setting as Default Terminal

Linux (update-alternatives):

sudo update-alternatives --install /usr/bin/x-terminal-emulator x-terminal-emulator /usr/bin/alacritty 50
sudo update-alternatives --config x-terminal-emulator

i3 Window Manager:

# In ~/.config/i3/config
bindsym $mod+Return exec alacritty

Shell Configuration

Add to your shell’s rc file:

# For tmux auto-attach
if [ -z "$TMUX" ]; then
    tmux attach -t default || tmux new -s default
fi

Performance Features

GPU Rendering

Alacritty uses OpenGL for rendering, providing:
– Smooth scrolling at high frame rates
– Minimal input latency
– Efficient memory usage
– Battery-friendly rendering

Benchmarking

Test scrolling performance:

time seq 1 100000

Compare with other terminals to see Alacritty’s speed advantage.

Advanced Features

Vi Mode

Enable Vi-like navigation:

[[keyboard.bindings]]
key = "Space"
mods = "Control|Shift"
action = "ToggleViMode"

In Vi mode:
– h/j/k/l for navigation
– v for visual selection
– y to yank
– / for search

URL Detection

Configure clickable URLs:

[hints]
enabled = [
  { regex = "(https?://)[a-zA-Z0-9._-]+(/[a-zA-Z0-9._/-]*)?" , hyperlinks = true, command = "xdg-open", binding = { key = "U", mods = "Control|Shift" } }
]

Live Reload

Configuration changes apply automatically without restart:

[general]
live_config_reload = true

Integration with Multiplexers

tmux Integration

Alacritty works excellently with tmux for splits and tabs:

# Launch with tmux
alacritty -e tmux

# Or configure in alacritty.toml
[terminal]
shell = { program = "/usr/bin/tmux", args = ["new-session", "-A", "-s", "main"] }

Zellij Alternative

[terminal]
shell = { program = "/usr/bin/zellij" }

Troubleshooting

Font Issues

Check available fonts:

fc-list | grep -i "mono"

Install Nerd Fonts:

brew tap homebrew/cask-fonts
brew install --cask font-jetbrains-mono-nerd-font

GPU Issues

Force software rendering:

LIBGL_ALWAYS_SOFTWARE=1 alacritty

Wayland Issues

Force X11 or Wayland:

WINIT_UNIX_BACKEND=x11 alacritty
WINIT_UNIX_BACKEND=wayland alacritty

Complete Configuration Example

# ~/.config/alacritty/alacritty.toml

[general]
live_config_reload = true
import = ["~/.config/alacritty/themes/dracula.toml"]

[window]
opacity = 0.92
blur = true
decorations = "full"
startup_mode = "Windowed"
dynamic_title = true

[window.dimensions]
columns = 140
lines = 45

[window.padding]
x = 12
y = 12

[scrolling]
history = 50000
multiplier = 3

[font]
size = 13.0

[font.normal]
family = "JetBrainsMono Nerd Font"
style = "Regular"

[cursor]
style = { shape = "Block", blinking = "On" }
blink_interval = 500

[selection]
save_to_clipboard = true

[terminal]
shell = { program = "/bin/zsh", args = ["-l"] }

Alacritty represents a modern approach to terminal emulation, proving that simplicity and performance need not be mutually exclusive. For users who value raw speed and are comfortable managing advanced features through external tools, Alacritty provides an uncompromising foundation for terminal-based workflows.