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Comment by adamch | Hacker News Reader

I've been using Kitty for a month now. I really like it. It's slightly less usable out of the box than iTerm 2. The default shortcuts are very counterintuitive (no CMD T for new tab or CMD W to close tab). But editing the preferences is straightforward.

I prefer it to iTerm because it's so. Damn. Fast. It's the only software (besides Sublime) I run on my laptop that actually feels like it's using the 40 years of transistor improvements I'm paying for.

I know iTerm recently added a Metal renderer but I need ligature support, which iTerm Metal doesn't have.

Maintainer has also been responsive on GitHub.

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It's the only software (besides Sublime) I run on my laptop that actually feels like it's using the 40 years of transistor improvements I'm paying for.

I wish more software fell into this category. It's still a little odd to me that something as conceptually simple as a terminal emulator should require a full blown GPU in order to perform smoothly.

It's more that we've introduced tons of layers between keypress and screen. This is very useful, but it introduces latency throughout the system. Figthing the latency while keeping the features means we have to adopt new techniques.

I think both Fish and Kakoune fall into this category. They're a shell and a CLI/TUI text editor that feel incredibly modern compared to their predecessors (i.e. Zsh and Vim).

Why? Everything that seems smooth is that way because of the GPU.

It's a terminal. Text on a plain background shouldn't be hard to do. It shouldn't involve lots of fancy hardware. We've been doing it for decades with significantly less latency on significantly slower hardware.

If you want to see just how fast it can be, grab a linux instance, press ctrl+f1 to drop to a GUI free terminal and see just how responsive and how fast it can run.

It's kind of nuts that we have to rely on something as powerful as hardware acceleration via GPU to make plain text rendering on a screen in a GUI approach the same speed as CPU rendered text in a straight terminal console.

To be fair, the text mode rendering you're using as a benchmark, is implemented in hardware as well.

Indeed, a more fair comparison is to compare GNOME Terminal to xterm. You should see that xterm is way faster, but it's also uglier and has far fewer features. Overhead isn't always about worthless bloat.

Until you think about how complex text is in a modern graphical environment. Thousands of different characters, many of which can compose, all vectors with curves that needs to be rendered, and visually optimised with regards to their position relative to the screen pixels, but also optimised wrt their size.

It's on some crazy high resolution display. If you switch to text mode, your resolution drops a ton, and the required pixel pushing power drops accordingly.

> I prefer it to iTerm because it's so. Damn. Fast.

Yup, I was also pretty surprised by this. I switched to Kitty recently, after terminology broke for me after an update. It's surprisingly hard to find terminal emulators that run on Xorg and on Wayland without making a fuzz.

Kitty does this beautifully and I had a real a-ha moment because of its speed the first time I tried it.

Have you managed to configure it to behave similar to iTerm 2 in terms of keyboard shortcuts? Would you please share your config?

One thing is, I don't get its layout, is it possible to create a vertical/horizontal split like what (shift+)cmd+d does in iTerm 2?

Ctrl-Shift-Enter opens a new "window" -- this is the terminology in the Kitty docs; it's a new terminal within the same frame, both being visible at the same time.

Ctrl-Shift-L goes through all enabled layouts. A layout specifies how the "windows" are arranged. Simple splits are available among others. I like the stacked layout: window 1 fills the full height on the left half of the screen, all other windows are stacked on the right half.

There does not seem to be a way to control the borders within the layout with the mouse; e.g. temporarily resize window 1 in the example above to be 80% of the width. That's something I sometimes miss. It's configurable, of course, but not ad hoc.

You can freely resize layouts using hte keyboard (but not the mouse) see https://sw.kovidgoyal.net/kitty/#layouts but be aware that it currently does not work in the released kitty because of a regression, so you will need to run kitty from master

Thanks, that's... certainly better than nothing. Works in the 0.11.3 release that I'm running.

It seems heavily inspired by xmonad.

That's something I really need as well - I like how fast kitty is compared to iterm2, but I'm just so used to using the splits in iterm2 + using a global keyboard shortcut to show and hide the terminal. I couldn't find anything similar in a quick glance over the config :/

For showing and hiding with a global keyword, couldn't you rely on your DE/WM to handle that for you?

Sorry, DE/WM? I assume WM is Window Manager, but can't think of what DE is, except Desktop something?

I'm using macOS and unfortunately not familiar with how I'd do that, but I'm sure it would be easy with something like i3wm on linux (which I still miss after moving away from linux 3 years ago :/), but I don't know what I could use in macOS.

Maybe I could find some third-party solution just to show/hide a particular application. I think if I had that + if I could figure out tabbing/tiling behaviour of Kitty, I would switch to it. Those two things are the main things that I need from iterm.

You can run a tiling window manager like i3 and xmonad on macOS! See:

https://github.com/ianyh/Amethyst

Global shortcut to bring up iterm2 is the main reason I use it!

From a marketing perspective I was wondering how did you discover it one month back? Product hunt? or here itself ?

It has been listed on the arch wiki under their list of available terminal emulators for a long time and I often use the wiki to look up things even when having to configure things on non-arch systems.

It's been meantioned on here a few times in conversation. That's how I stumbled across Kitty.

https://lwn.net/Articles/753029/

It's easy to find if you search for terminal emulators with low latency.

Different conclusion for the same article: I picked mlterm

https://anarc.at/blog/2018-05-04-terminal-emulators-2/

I wanted to try a new terminal, so I looked up the terminal latency comparison article that was making the rounds a few months ago. Of the ones that ran on OSX, Kitty seemed to be worth trying.

Do you use tmux? The tmux/vim combo on MacOS seems to have minimal performance gains when using GPU accelerated terminals, unfortunately.

This is what I was curious about as well. Screenshot shows a split screen though so perhaps some tmux-like functionality is available natively?

Indeed, it is! And I find that it's much better than tmux performance-wise.

Could you share your config that makes Kitty behave more like iTerm 2?

As another user of iTerm2, I am currently using several keyboard mappings from key to key (like Tab being interpreted as Esc), do you know whether Kitty supports that? As far as I can see in the docs, only examples of key to action are shown.

You could do that at the macOS level using karabiner for example. I have Caps lock as esc when tapped and Ctrl when held.

Why do you need ligature support?

Not OP, but they are an essential component of some languages' writing systems, so it could be that.

If you code in the console with this : https://github.com/tonsky/FiraCode ??? Dunno...

In this case, it's more of a 'nice to have' feature than a 'I need it' feature.

Ligatures make Haskell, Rust and JS roughly 18 times more readable, I've gotten so used to them that I hate reading code without them.

iTerm's 2 global hotkey + half screen pane combo has been stuck on it. Not gonna leave until I can do the same with another terminal emu.

I'm having trouble putting this into words without sounding smarmy, so please, that's not my intention.

How are you attributing speed to Kitty over iTerm? Wouldn't most of the sluggishness of anything be more attributed to the programs you're running in the terminal?

Try it. You'll be surprised. An amazing amount of lag comes from the routines needed to display the text some utility prints, not the utility itself.

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