How to reduce ghostty startup timecost?

[eval-exec]

❯ time ghostty -e exit
info: ghostty version=1.1.3-e07b6fd-nix
info: ghostty build optimize=ReleaseFast
info: runtime=apprt.Runtime.gtk
info: font_backend=font.main.Backend.fontconfig_freetype
info: dependency harfbuzz=10.0.1
info: dependency fontconfig=21500
info: renderer=renderer.OpenGL
info: libxev default backend=io_uring
info(os): setlocale from env result=en_US.UTF-8
info(gtk): GTK version build=4.16.7 runtime=4.16.7
info(gtk): libadwaita version build=1.6.2 runtime=1.6.2
info: reading configuration file path=/home/exec/.config/ghostty/config
info(config): default shell source=env value=/run/current-system/sw/bin/zsh
warning(gtk): setting GDK_DEBUG=gl-no-fractional
warning(gtk): setting GDK_DISABLE=gles-api,color-mgmt,vulkan
warning(gtk): setting GSK_RENDERER=opengl
Unrecognized value "color-mgmt". Try GDK_DISABLE=help

(process:112616): Adwaita-WARNING **: 20:24:02.641: Using GtkSettings:gtk-application-prefer-dark-theme with libadwaita is unsupported. Please use AdwStyleManager:color-scheme instead.
info(grid): loaded OpenGL 4.6
info(io_exec): found Ghostty resources dir: /nix/store/sjyln4diqzd16hsv11dz51rcpsja3cds-ghostty-1.1.3/share/ghostty
warning(io_exec): shell could not be detected, no automatic shell integration will be injected
warning(gtk): unimplemented action=apprt.action.Action.Key.cell_size

(process:112616): Gtk-WARNING **: 20:24:03.160: No IM module matching GTK_IM_MODULE= found
info(io_exec): started subcommand path=/bin/sh pid=112659
info(io_exec): subcommand cgroup=-
info(io_exec): pty fd closed, read thread exiting
info(surface): surface closed addr=55b2abfddcb0
ghostty -e exit  0.47s user 0.24s system 108% cpu 0.655 total

ghostty need 0.655 s to startup.
compareto alacritty:

Error: Custom { kind: NotFound, error: "Failed to spawn command 'exit': No such file or directory (os error 2)" }
alacritty -e exit  0.09s user 0.06s system 72% cpu 0.209 total

compare to st:

❯ time st -e sh -c date
st -e sh -c date  0.03s user 0.02s system 69% cpu 0.068 total

It seems that ghostty startup is too long. how to reduce it?

[eval-exec]

It seems that
The log info(grid): loaded OpenGL 4.6 cost almost 0.4s.

[rhodes-b]

Yes GTK has a known startup cost ghostty cant really do anything about if you want you can add a background ghostty in whatever login system you perfer (systemd for example) with ghostty -initial-window=false -quit-after-last-window-closed=false -gtk-single-instance=true

Otherwise in general you should add gtk-single-instance=true inside your config as it makes only the first launch of ghostty take the 600ms to startup any new terminal after that will be very quick

You cant compare allacrity, kitty etc they are using very minimal custom frameworks while Ghostty is using GTK

[pluiedev]

A much fairer comparison would be with other GTK 4-based terminals like Ptyxis and GNOME Console. I'm not surprised if we're still slower in that regard since we load a lot of things before startup, which could be optimized.

[00-kat]

ghostty -initial-window=false -quit-after-last-window-closed=false -gtk-single-instance=true

That should be:

ghostty --initial-window=false --quit-after-last-window-closed=false --gtk-single-instance=true