[hxorr]

Firefox android doesn't allow opening local file:// HTML files due to their poor sandboxing / security (I don't remember the specifics)

I like the browsing experience a lot but there are a few rough edges for sure.

[bogwog]

Just serve them through any http server on termux! Works as you'd expect, but on FF you need to manually add the http:// prefix in the URL bar if you navigate to an IP address like 127.0.0.1. Not sure why it doesn't figure that out by itself.