GitComet

Fastest Open Source Git GUI

GitComet is built for teams that want fast Git operations with local-first privacy, familiar workflows, and open source freedom.

Available for Linux, Windows, and macOS.

Download

Download the latest prebuilt binaries/installers from GitHub Releases.

Homebrew

install app from tap (recommended):

brew tap auto-explore/gitcomet
brew install --cask gitcomet

MacOS Troubleshooting: If you downloaded the app manually and macOS reports that GitComet "is damaged and can't be opened", this is due to Apple's Gatekeeper quarantine for apps downloaded outside the App Store. To resolve this, run the following command in your terminal to remove the quarantine attribute:

xattr -d com.apple.quarantine /Applications/GitComet.app

optional CLI install:

brew install gitcomet-cli

Fast, Free, Familiar

• Fast: Built end-to-end in Rust for speed and efficiency using smol, gix, and gpui.
• Free: Free to use for individuals and organizations.
• Familiar: Familiar history browsing and drop-in git difftool and git mergetool compatibility.

Why GitComet

GitComet started from frustration with existing tools on huge codebases like Chromium. We could not find a product that stays responsive and functional when browsing large repositories and file diffs.

Chromium benchmark snapshot

Tool	Version	Time to open Chromium repo	Memory while opening
GitComet	v0.2.0	1s	265MB
GitFiend	v0.45.3	1s	289MB
SmartGit	v25.1.110	18s	4.8GB
GitKraken	v11.10.0	25s	2GB
Megit	v0.10.0	29s	14.4GB
Gittyup	v2.0.0	43s	2.5GB + 1.5GB indexer

Measured on Linux 6.19.6-zen (x64), Ryzen 5950x, 128GB DDR4. Detailed test steps will be published.

Editions (planned)

Open Source

• Price: €0 forever
• Usage: Free for personal and commercial use
• Includes:
  • Full local-first desktop workflow
  • Git remotes, pull/push, staging, commits
  • Worktrees, branching, and full history
  • Multi-repository browsing
  • Inline and side-by-side diffs
  • 2-way and 3-way merge tools

Professional

• Price: €20 lifetime access (limited-time early adopter offer)
• Includes everything in Open Source, plus:
  • Claude Code, Codex, and GitHub CLI integrations
  • Code test coverage workflows
  • GitHub and Azure DevOps integrations
  • Priority improvements during early access
• Join waitlist: gitcomet.dev/#pricing

Build from source

cargo build -p gitcomet --features ui-gpui,gix
cargo run -p gitcomet --features ui-gpui,gix -- /path/to/repo

Contributing

Developer setup, workspace layout, testing, and coverage docs live in CONTRIBUTING.md.

Using as a Git difftool / mergetool

GitComet can be used as a standalone diff and merge tool invoked by git difftool and git mergetool. It supports both headless (algorithm-only) and GUI (interactive GPUI window) modes.

Setup / uninstall (recommended)

# Configure Git globally to use GitComet for both difftool + mergetool
gitcomet setup

# Remove GitComet integration safely
gitcomet uninstall

• Use --local to target only the current repository instead of global config.
• Use --dry-run to print the commands before applying changes.

This setup registers both headless and GUI variants with guiDefault=auto, so Git chooses GUI when display is available and falls back to headless otherwise. setup/uninstall are designed to be idempotent.

Show detailed setup/uninstall behavior and manual commands

Built-in setup writes these Git config entries:

GITCOMET_BIN="/absolute/path/to/gitcomet"

# Headless tool: algorithm-only merge/diff for CI, scripts, and no-display environments
git config --global merge.tool gitcomet
git config --global mergetool.gitcomet.cmd \
  "'$GITCOMET_BIN' mergetool --base \"\$BASE\" --local \"\$LOCAL\" --remote \"\$REMOTE\" --merged \"\$MERGED\""
git config --global mergetool.trustExitCode true
git config --global mergetool.gitcomet.trustExitCode true
git config --global mergetool.prompt false

git config --global diff.tool gitcomet
git config --global difftool.gitcomet.cmd \
  "'$GITCOMET_BIN' difftool --local \"\$LOCAL\" --remote \"\$REMOTE\" --path \"\$MERGED\""
git config --global difftool.trustExitCode true
git config --global difftool.gitcomet.trustExitCode true
git config --global difftool.prompt false

# GUI tool: opens focused GPUI windows for interactive diff/merge
git config --global merge.guitool gitcomet-gui
git config --global mergetool.gitcomet-gui.cmd \
  "'$GITCOMET_BIN' mergetool --gui --base \"\$BASE\" --local \"\$LOCAL\" --remote \"\$REMOTE\" --merged \"\$MERGED\""
git config --global mergetool.gitcomet-gui.trustExitCode true

git config --global diff.guitool gitcomet-gui
git config --global difftool.gitcomet-gui.cmd \
  "'$GITCOMET_BIN' difftool --gui --local \"\$LOCAL\" --remote \"\$REMOTE\" --path \"\$MERGED\""
git config --global difftool.gitcomet-gui.trustExitCode true

# Auto-select GUI tool when DISPLAY is available, headless otherwise
git config --global mergetool.guiDefault auto
git config --global difftool.guiDefault auto

Built-in setup stores previous user values for shared generic keys under gitcomet.backup.* (when needed).
Built-in uninstall restores those backups only when the key still has the setup-managed value. If the user changed a setting after setup, uninstall preserves that user-edited value and then removes GitComet-specific keys.

CLI modes

Difftool:

gitcomet difftool --local <path> --remote <path> [--path <display_name>] [--label-left <label>] [--label-right <label>]

Also reads LOCAL/REMOTE from environment as a fallback when invoked by Git.

Mergetool:

gitcomet mergetool --local <path> --remote <path> --merged <path> [--base <path>] [--label-local <label>] [--label-remote <label>] [--label-base <label>]

Also reads LOCAL/REMOTE/MERGED/BASE from environment. Base is optional for add/add conflicts.

Compatibility

KDiff3 and Meld invocation forms are supported (--L1/--L2/--L3, -o/--output/--out, --base, positional arguments), so GitComet can be a drop-in replacement.

Crash logs

If the app crashes due to a Rust panic, GitComet writes a crash log to:

• Linux: $XDG_STATE_HOME/gitcomet/crashes/ (fallback: ~/.local/state/gitcomet/crashes/)
• macOS: ~/Library/Logs/gitcomet/crashes/
• Windows: %LOCALAPPDATA%\gitcomet\crashes\ (fallback: %APPDATA%\gitcomet\crashes\)

On next startup, GitComet can prompt you to report the crash as a prefilled GitHub issue in Auto-Explore/GitComet, including app version, platform, panic details, and a trimmed backtrace.

Prior work and ideas inspired by:

SourceTree, GitKraken, Zed, GPUI, KDiff3, Meld, Github Desktop, Git, Gix, Rust, Smol, and many more.

This project has been created with the help of AI tools, including OpenAI Codex and Claude Code.

Star History

License

GitComet is licensed under the GNU Affero General Public License Version 3 (AGPL-3.0-only). See LICENSE-AGPL-3.0.

Copyright (C) 2026 AutoExplore Oy
Contact: info@autoexplore.ai