Why you choose to base this off of TeX Live 2020? Is that just when you initially started the project, or are there some incompatibilities with the later versions?
Also, we (the TeX Live team) would be happy to add Wasm as an officially-supported platform, it's just that nobody has volunteered yet [0]. Coincidentally, someone else suggested something similar to us a few months ago [1]. Feel free to reach out if you're interested.
[0]: https://tug.org/texlive/build.html#volunteers
[1]: https://github.com/TeX-Live/texlive-source/issues/87
The 2020 part isn't really something I chose, it comes with the SwiftLaTeX engine, which ships a precompiled format from that era. I just inherited it with the engine.
The format and packages have to agree, and when I pulled in newer packages against that old format, some things broke (hyperref had changed its aux label format, for which I ended up backporting a padding fix, and babel was missing some aliases in the mismatched version, e.g. brazil-portuges).
And yes, I'd be very happy to help with that and will get in touch via the volunteers page!
Does this work on Firefox or Safari? You say “Firefox or Safari fall back to a virtual filesystem” but somehow I can’t get this fallback to work. When I click New Project I just get a reminder to use Chrome or Edge. Is there a button to press to trigger the fallback?
I'm on Safari, and it seems you can open your local LaTeX file to use the tool. It's an “Open file” button at the top.
Although I agree that it would be cool to have some hello-world example pre-opened.
The hello-world example sounds like a good idea, I'll try to add that as well, so that the user lands on a working document.
Ooh. That worked. Thanks.
There's no button (that's a gap on my side, not intended behavior). New Project currently goes only through the folder picker, so on Firefox or Safari it just stops there. The virutal filesystem fallback is only in Open File, which is also why zahrevsky's workaround gets you in.
I'll make New Project also fall back the same way, so it works in Firefox and Safari without the detour.
I love this use of wasm!
I never really got the hang of LaTeX but I've really enjoyed Typst the past few years and even made a few books with it. Have you ever tried that or have thought on it?
I copy-pasted a random LaTeX doc from many years ago (I made sure I wrote it before 2020 so it did not use any new features not in TeX Live 2020), and upon compilation I got the error
Font OT1/cmr/m/n/10.95=cmr10 at 10.95pt not loadable: Bad metric (TFM) file.
on line 13017. The document had only 200 lines so this must be from a package. It was really not clear where the error was coming from. I guessed that it was coming from \usepackage{microtype}, so I commented it out, but the same error persisted.
I decided to hard refresh the tab and this time I got a different error:
TeX capacity exceeded, sorry [text input levels=15].
on line 39. Again it was unclear line 39 of which package.
Can't tell much from those two lines, but if you open an issue with the document, or just provide the full compile log, I could dig into it.
The TFM error usually means a font file wasn't available. However, the service worker validates the downloads before caching, so any error pages or empty bodies get rejected (which makes posoned cache unlikely), but a stale state may still be possible.
Hard refresh bypasses the service worker, I patched around that last month but apparently not well enough.
Also, better error logs and reporting is already on my ToDo-list, sorry for that.
This is super cool. I wish there was something like this for ConTeXt too.
Interesting. I usually use pandoc for converting my Markdown, which goes via LaTeX. Is there a specific reason you picked ConTeXt?
> I usually use pandoc for converting my Markdown
See my Typesetting Markdown series:
https://dave.autonoma.ca/blog/2019/05/22/typesetting-markdow...
> Is there a specific reason you picked ConTeXt?
LaTeX:
* doesn't (easily, or practically) separate content from presentation;
* has arcane, antiquated syntax;
* packages can have namespace conflicts (rare, but happens);
* requires package installation for additional features.
ConTeXt, being monolithic and newer, avoids all those issues. The feature matrix lists a number of samples typeset with ConTeXt:
https://keenwrite.com/blog/2025/09/08/feature-matrix/
FWIW, pandoc has the ability to generate ConTeXt code.
My project https://latex.to supports ConTeXt (plus all other TeX Live engines). Click + then New from showcase then ConTeXt to try it.
Cool! But it appears to always use LuaTeX as the engine, so only the older MkIV format is supported, and not the current LMTX format. The caching also doesn't seem to work quite right, since it appears to regenerate the font caches every time that you run it, which makes recompiles quite slow.
Anyone know if this includes TikZ?
Yes, tikz.sty, pgf.sty and pgfplots.sty are in the bundled subset (it's around 360 pgf related files that ship with the app). Only the graph drawing sublibrary requires LuaTeX, so that one won't work.
Cool, this project looks very interesting!
I tried uploading a .tex file created earlier this year and was able to see a PDF preview without any additional configuration.
As someone who has a local TeX setup, I'm a fan of your approach to loading dependencies on demand with a service worker. The installation process on my computer took a while because it was downloading a bunch of dependencies I didn't need.