Show HN: Chawan TUI web browser

7 months ago (chawan.net)

A terminal-based web browser in Nim.[1] Has acceptable (YMMV) CSS rendering, some JS support, and inline images (sixel/kitty). It can also use various protocols other than http(s) such as (s)ftp, gopher, gemini, ...

Chawan started out as a w3m clone, and the UI still resembles it. However, the architecture has turned out quite different, with pages loaded in separate processes, and protocol/file type handling separated out into external binaries. An interesting result is that you can even register decoders for custom inline image formats, although practical use cases of this are rather minimal.

There is a gallery showcasing some websites being rendered here: https://chawan.net/gallery/index.html

[1]: https://nim-lang.org

Thanks, always appreciate ways of not using another blink engine for a brief research side quest! looking forward to test after school ; )

As it hasn't been brought up yet, a really great hack (esp. for us without sixel) is this terminal port of chromium: https://github.com/fathyb/carbonyl .. but the original creator hasn't had time to get back to it. So it is very bare bones & lacks a lot of features, like keyboard shortcuts, file saving.. but obviously it brings full web compatibility and is just very cool. Wishing for someone with rust skills to pick it up again, last time I looked (couple of months ago) none of the forks had any momentum.

  • Side note but on the carbonyl github post, everyone keeps asking about the author's health as if he's safe or not, given he is palestinian.

    I hope the author is safe. His work was really good,I must say. Fuck wars in general.

    • Well his github profile says he's in France, so let's hope he's kinda safe.. But yeah, fuck wars in general. Also, fuck the generals.. and their commanders. Oh, and the whole military-industrial complex as well. We urgently need a transition towards a planetary non-commercial commons-based economy..

@shiomiru

What's the best resource (paid or free) in your opinion for learning about these TTY related concepts?

I'm aware of https://www.linusakesson.net/programming/tty/index.php for example, but that doesn't go into termcap/terminfo/curses.

one of the comments mentions http://www.amazon.com/termcap-terminfo-OReilly-Nutshell-Lind... though (online https://www.scribd.com/document/831486848/Termcap-and-Termin...)

This is super cool! Bravo. Awesome to see it written in Nim too.

When I do `cha example.com` I can't figure out how to use any of the commands (hjkl, etc). The only keys I've found that have any effect are typing numbers which show up in the bottom left. Haven't figured out how to do anything with those. Am I missing something obvious about how to use this or could this be a bug?

I built from source on MacOS Sequoia 15.5 Apple Silicon using Nim 2.24. Pages load correctly, I just can't get the commands to work. Thanks!

Very nice! I compiled this from source on my Lenovo M8 4h gen running termux: I only had to install nim. It even installed nicely despite there being no "root" user.

I've always tried to make my websites look good in Links and now it looks like I have a new candidate.

Having support for some CSS makes it a bit more difficult, as spacing between elements is now an issue, where previously links would ignore margins and padding all together which were used to display cleaner inline list elements (for menus and such).

  • The intention is that it should "just work"... I'm aware sometimes it doesn't, you can consider that a bug :)

    But if you really want custom CSS for grid displays, chawan does support the standard "grid" media feature: https://developer.mozilla.org/en-US/docs/Web/CSS/@media/grid

    • I had no idea this CSS API existed. I'll add that to my CSS, thank you! :)

      I'll check if the issue tracker has anything related to supporting titled alternate stylesheets (and eventually allowing users to pick one of them), because on the website where I made efforts for the markup to look reasonable on links, I also have a "simple" style that removes most of the CSS fanciness.

Long time w3m user here. Tried it and I can love it. Very nice.

Is that your design choice not having "Open URL"(Address bar) feature?

Wonderful! Thanks!

I see you don't use termcap/ncurses anymore. Do you perform terminal handling yourself directly?

Thanks again!

  • Chawan never really used ncurses, only termcap. (ncurses just happens to implement termcap too.)

    I started with termcap because I was already familiar with it through w3m. But termcap is an obsolete interface, and cannot describe the only useful attribute for modern terminals (true color). Its only benefit was "maybe it accidentally works on a hardware terminal from the 80s", which is cool but not really worth the extra failure mode.

    So instead of migrating to terminfo, I ditched it completely in favor of terminal queries (which were already necessary for other reasons). There is still a built-in terminal database, to detect known TERM values with XTerm incompatibilities. But a terminal that correctly responds to queries will work out of the box, even if its TERM value is unknown.

    • > I started with termcap because I was already familiar with it through w3m. But termcap is an obsolete interface, and cannot describe the only useful attribute for modern terminals (true color). Its only benefit was "maybe it accidentally works on a hardware terminal from the 80s", which is cool but not really worth the extra failure mode.

      Priorities, I guess. As long as I'm in a terminal, I'd rather have support for hardware terminals from the 80s than truecolor. But my only hardware terminal is a VT-420, so probably works for more or less anything that supports base XTerm (monochrome).

Finally a good tool to view HN in terminal. Thank you! Where can I find the keyboard shortcuts? I can move with vim key binding, but can go back.

always nice to see something written in nim. In my very novice eyes, it is the most interesting language that is situated between C/C++ and python. It's a pity it never took off. The productivity of its users compared to the userbase size always made me think I'm right even if I'm far to be knowledgeable enough on the topic

  • Nim(rod) was released soon before Golang, and the overlap in features probably stopped the former one.

Can be easily built on macOS with just a single 'make'. Cool.

And nice to see there's a new elinks alternative.

This works great, been playing with it through s-search and it works way better than w3m. =)

I recommend perusing the code. Since it’s in Nim it’s pretty approachable (and performant). There’s still lots of gnarly bits like implementing HTML DOM and web specs, but it doesn’t take you days to grasp the basic setup.

How are those images rendered in text UI?

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  • > terminal browsers are hobby projects because

    ...those pesky GUI users want pixel-precision :P

    Surely it's a hobby project. You have to have very specific tastes to browse in the terminal in 2025.

    > using external binaries for protocols feels like sidestepping the real engineering

    You could easily move all protocols to the main binary. The reason for the current arrangement is that this way, you can e.g. replace the HTTP handler with curl-impersonate, or add custom protocols like magnet (etc.) See the bonus directory in the sources for inspiration.

    > tied to niche image formats like sixel/kitty which barely anyone supports.

    Sixel & Kitty are the only image formats anybody supports. The alternatives are ASCII art (fun, but too pixelated) & hacking images onto the terminal thru the display server (is that still a terminal-based app?) But I'm happy to discuss further, I find the issue fascinating :)

    > mac

    The macOS issue is largely a function of the only person working on this not having a mac. If you do, you can help solving it by debugging it yourself & posting the results: https://todo.sr.ht/~bptato/chawan/63