Reading up on Ghostty

Ghostty is now indisputably the fastest terminal emulator at IO throughput, by a very large margin. On ASCII, Unicode, and CSI tests, Ghostty is more than 2x (double!) faster than any other leading "fast" terminal. These changes are directly in libghostty, too, so everyone wins. `time cat 150MB_ascii.txt`: - Ghostty nightly: 575ms - Ghostty 1.3.2: 1.5sec - Alacritty: 1.2sec - Kitty: 1.7sec - Warp: 3.8sec - iTerm2, Terminal: stopped after 60s `time cat 150MB_unicode.txt` (mixed languages): - Ghostty nightly: 536ms - Ghostty 1.3.2: 1.22sec - Alacritty: 1.05s - Kitty: 1.35s - Warp: 3.4s - iTerm2, Terminal: stopped after 60s `DOOM-Fire-Zig` (an IO test): - Ghostty nightly: 842fps - Ghostty 1.3.2: 532fps - Kitty: 485fps - Alacritty: 593fps - Warp: 577fps - iTerm2, Terminal: 60fps (yes, 60) To quickly address the "cat speed doesn't matter" naysayers: this is a direct test of how many bytes/second you can push through a terminal. It doesn't cover just "read big file" but also "how much can a TUI do". The tests above test various shapes of inputs (plain ascii, unicode/wide chars, csi-heavy loads, etc.). IO throughput is incredibly important. Most of these improvements apply to libghostty-vt consumers too, so any libghostty-based terminals will instantly see huge throughput improvements by simply upgrading (ABI compatible). I'll cover the exact improvements in a blog post in the future. These results are the result of 6 separate optimizations.

@mitchellh

Mind boggling to me that I can make a thing faster and there's always people that ask "but why?" What kind of mentality is that? The pursuit of excellence does not need justification. Also, I find in so many cases, we can't know the impact of an improvement until we do it. For example, one I've talked about before: Ghostty's high IO throughput has enabled terminal program (emulator and TUI) fuzzing at a speed thats incomparably fast to prior solutions. This has resulted in upstream patches to resolve issues in popular projects like btop, tmux, and more. Speed enabled that anecdotally example that lifted the tides of adjacent communities that don't rely on Ghostty technology at all. I didn't predict this. Make things better because they can be better and let the results naturally play out.

@mitchellh

Still limited by compute, so I built a thing that runs codex in the cloud, powered by @Cloudflare firecracker boxes (and since that's not beefy enough for larger projects, tests are run via crabbox) Uses Ghostty ofc, via WebAssembly. Codex replicated itself, basically.

@steipete

Awesome to see! Let's replace the Alacritty core with libghostty-rs. If there are any shortcomings in the libghostty API I'll address them immediately. I know some view Ghostty as competitive to Warp at a GUI level, but the goal was always to empower other terminal apps via libghostty and there was no other vehicle to get that out than to build a GUI too (similar to Alacritty and their vte crate). I don't think I've ever talked negatively about Warp online (except maybe the login thing they fixed ages ago), I've always respected that they're trying something different. I know Warp has moved on to being a much bigger vision than "just" a terminal, but let's modernize that terminal core. :)

@mitchellh

Another day another libghostty-based project, this time a macOS terminal with vertical tabs, better organization/notifications, embedded/scriptable browser specifically targeted towards people who use a ton of terminal-based agentic workflows. https://t.co/9SLNCxM21S

@mitchellh

Next version of Omarchy will have a delightfully configured Tmux setup out of the box. Many terminals, including Ghostty, have panes and tabs built-in, but let me show you why I've still come to prefer Tmux. pic.twitter.com/AhKJT7vwtC

@dhh

Writebook is going open source in a not too-distant future, but before then, I still want markdown exports of all my Omarchy manuals to feed to LLMs. So giving Codex 5.2 the first shot at an implementation. Love this split with Ghostty! pic.twitter.com/eL8Tr9Jttj

@dhh

Web interface for terminal configurationhttps://t.co/deQjJEc1e2 pic.twitter.com/yecQZsfQrG

@tom_doerr

Here's a short video (4m) that goes into more detail on how "vim mode" works in Ghostty and the multitude of features that are composed together to make it all work. This showcases how powerful Ghostty's keybinding system is getting!And don't worry, I plan on shipping a… pic.twitter.com/3flwhCiWEf

@mitchellh

The lack of "feature design" is why so many products over time feel hollow or messy. This isn't visual design. This isn't architectural design. I thought that a short video lecture of what feature design is and a real case study of applying it in Ghostty would be helpful.… pic.twitter.com/XIYmPhXojE

@mitchellh

Omarchy 3.2 is out! @mitchellh's Ghostty is the new default terminal, @tobi's Try is included, new stable mirror/pkg repo, TUI for bluetooth, two new themes, visual theme picker, and SO MUCH MORE! https://t.co/9irAh5Gh63 pic.twitter.com/4MHuOnykfO

@dhh