Ghostty

Fast, native, feature-rich terminal emulator pushing modern features.
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About

Ghostty is a terminal emulator that differentiates itself by being fast, feature-rich, and native. While there are many excellent terminal emulators available, they all force you to choose between speed, features, or native UIs. Ghostty provides all three.

In all categories, I am not trying to claim that Ghostty is the best (i.e. the fastest, most feature-rich, or most native). But Ghostty is competitive in all three categories and Ghostty doesn't make you choose between them.

Ghostty also intends to push the boundaries of what is possible with a terminal emulator by exposing modern, opt-in features that enable CLI tool developers to build more feature rich, interactive applications.

While aiming for this ambitious goal, our first step is to make Ghostty one of the best fully standards compliant terminal emulator, remaining compatible with all existing shells and software while supporting all of the latest terminal innovations in the ecosystem. You can use Ghostty as a drop-in replacement for your existing terminal emulator.

For more details, see About Ghostty.

Download

See the download page on the Ghostty website.

Documentation

See the documentation on the Ghostty website.

Roadmap and Status

The high-level ambitious plan for the project, in order:

#	Step	Status
1	Standards-compliant terminal emulation	✅
2	Competitive performance	✅
3	Basic customizability -- fonts, bg colors, etc.	✅
4	Richer windowing features -- multi-window, tabbing, panes	✅
5	Native Platform Experiences (i.e. Mac Preference Panel)	⚠️
6	Cross-platform libghostty for Embeddable Terminals	⚠️
7	Windows Terminals (including PowerShell, Cmd, WSL)	❌
N	Fancy features (to be expanded upon later)	❌

Additional details for each step in the big roadmap below:

Standards-Compliant Terminal Emulation

Ghostty implements enough control sequences to be used by hundreds of testers daily for over the past year. Further, we've done a comprehensive xterm audit comparing Ghostty's behavior to xterm and building a set of conformance test cases.

We believe Ghostty is one of the most compliant terminal emulators available.

Terminal behavior is partially a de jure standard (i.e. ECMA-48) but mostly a de facto standard as defined by popular terminal emulators worldwide. Ghostty takes the approach that our behavior is defined by (1) standards, if available, (2) xterm, if the feature exists, (3) other popular terminals, in that order. This defines what the Ghostty project views as a "standard."

Competitive Performance

We need better benchmarks to continuously verify this, but Ghostty is generally in the same performance category as the other highest performing terminal emulators.

For rendering, we have a multi-renderer architecture that uses OpenGL on Linux and Metal on macOS. As far as I'm aware, we're the only terminal emulator other than iTerm that uses Metal directly. And we're the only terminal emulator that has a Metal renderer that supports ligatures (iTerm uses a CPU renderer if ligatures are enabled). We can maintain around 60fps under heavy load and much more generally -- though the terminal is usually rendering much lower due to little screen changes.

For IO, we have a dedicated IO thread that maintains very little jitter under heavy IO load (i.e. cat <big file>.txt). On benchmarks for IO, we're usually within a small margin of other fast terminal emulators. For example, reading a dump of plain text is 4x faster compared to iTerm and Kitty, and 2x faster than Terminal.app. Alacritty is very fast but we're still around the same speed (give or take) and our app experience is much more feature rich.

Note

Despite being very fast, there is a lot of room for improvement here.

Richer Windowing Features

The Mac and Linux (build with GTK) apps support multi-window, tabbing, and splits.

Native Platform Experiences

Ghostty is a cross-platform terminal emulator but we don't aim for a least-common-denominator experience. There is a large, shared core written in Zig but we do a lot of platform-native things:

• The macOS app is a true SwiftUI-based application with all the things you would expect such as real windowing, menu bars, a settings GUI, etc.
• macOS uses a true Metal renderer with CoreText for font discovery.
• The Linux app is built with GTK.

There are more improvements to be made. The macOS settings window is still a work-in-progress. Similar improvements will follow with Linux.

Cross-platform libghostty for Embeddable Terminals

In addition to being a standalone terminal emulator, Ghostty is a C-compatible library for embedding a fast, feature-rich terminal emulator in any 3rd party project. This library is called libghostty.

This goal is not hypothetical! The macOS app is a libghostty consumer. The macOS app is a native Swift app developed in Xcode and main() is within Swift. The Swift app links to libghostty and uses the C API to render terminals.

This step encompasses expanding libghostty support to more platforms and more use cases. At the time of writing this, libghostty is very Mac-centric -- particularly around rendering -- and we have work to do to expand this to other platforms.

Crash Reports

Ghostty has a built-in crash reporter that will generate and save crash reports to disk. The crash reports are saved to the $XDG_STATE_HOME/ghostty/crash directory. If $XDG_STATE_HOME is not set, the default is ~/.local/state. Crash reports are not automatically sent anywhere off your machine.

Crash reports are only generated the next time Ghostty is started after a crash. If Ghostty crashes and you want to generate a crash report, you must restart Ghostty at least once. You should see a message in the log that a crash report was generated.

Note

Use the ghostty +crash-report CLI command to get a list of available crash reports. A future version of Ghostty will make the contents of the crash reports more easily viewable through the CLI and GUI.

Crash reports end in the .ghosttycrash extension. The crash reports are in Sentry envelope format. You can upload these to your own Sentry account to view their contents, but the format is also publicly documented so any other available tools can also be used. The ghostty +crash-report CLI command can be used to list any crash reports. A future version of Ghostty will show you the contents of the crash report directly in the terminal.

To send the crash report to the Ghostty project, you can use the following CLI command using the Sentry CLI:

SENTRY_DSN=https://e914ee84fd895c4fe324afa3e53dac76@o4507352570920960.ingest.us.sentry.io/4507850923638784 sentry-cli send-envelope --raw <path to ghostty crash>

Warning

The crash report can contain sensitive information. The report doesn't purposely contain sensitive information, but it does contain the full stack memory of each thread at the time of the crash. This information is used to rebuild the stack trace but can also contain sensitive data depending when the crash occurred.

Developing Ghostty

See the documentation on the Ghostty website for building Ghostty from source. For development, omit the -Doptimize flag to build a debug build.

On Linux or macOS, you can use zig build -Dapp-runtime=glfw run for a quick GLFW-based app for a faster development cycle while developing core terminal features. Note that this app is missing many features and is also known to crash in certain scenarios, so it is only meant for development tasks.

Other useful commands:

• zig build test for running unit tests.
• zig build test -Dtest-filter=<filter> for running a specific subset of those unit tests
• zig build run -Dconformance=<name> runs a conformance test case from the conformance directory. The name is the name of the file. This runs in the current running terminal emulator so if you want to check the behavior of this project, you must run this command in Ghostty.

Linting

Prettier

Ghostty's docs and resources (not including Zig code) are linted using Prettier with out-of-the-box settings. A Prettier CI check will fail builds with improper formatting. Therefore, if you are modifying anything Prettier will lint, you may want to install it locally and run this from the repo root before you commit:

prettier --write .

Make sure your Prettier version matches the version of Prettier in devShell.nix.

Nix users can use the following command to format with Prettier:

nix develop -c prettier --write .

Alejandra

Nix modules are formatted with Alejandra. An Alejandra CI check will fail builds with improper formatting.

Nix users can use the following command to format with Alejanda:

nix develop -c alejandra .

Non-Nix users should install Alejandra and use the following command to format with Alejandra:

alejandra .

Make sure your Alejandra version matches the version of Alejandra in devShell.nix.

Updating the Zig Cache Fixed-Output Derivation Hash

The Nix package depends on a fixed-output derivation that manages the Zig package cache. This allows the package to be built in the Nix sandbox.

Occasionally (usually when build.zig.zon is updated), the hash that identifies the cache will need to be updated. There are jobs that monitor the hash in CI, and builds will fail if it drifts.

To update it, you can run the following in the repository root:

./nix/build-support/check-zig-cache-hash.sh --update

This will write out the nix/zigCacheHash.nix file with the updated hash that can then be committed and pushed to fix the builds.