You are building some HTML page. You can do some things things with an HTML files on your hard disk, although these are locked down for security reasons.
So you run a local server to serve those files an dhave your browser treat them like part of the real internet.
Usually for local testing, serving the files unencrypted (plain HTTP) is enough; sometimes you need to do encrypted (keywords: HTTPS/SSL/TLS) which is a whole nother thing.
Here are two that are likely to work with no further fuss.
Bareback feature-free somehow-works HTTP with netcat:
nc -l 127.0.0.1 8889 < foo.html
This is reasonably simple and serves static files with little fuss.
python3 -m http.server --bind 127.0.0.1
Caddy, is a free and open source server, and that will get you a long way. USP: it supports automatic [SSL]](./secure_servers.html), which is handy. It has plugins upporting totally nuts features such as AWS lambda function proxying and automatic hugo for plain text blogging.
npm builtin servers
For node browser apps, e.g. beefy
and run-browser and
their ilk might work and probably integrate with your build process.
There are so many different options for
node that I usually pass over it in choice-paralyzed silence.
Fenix is a GUI wrapped around a node-style server that promises advanced debugging/introspection features. But I haven’t useed it and it doesn’t run on Linux, so ignoring for now.
Oh wait but I need SSL
Crap. I understand, but this is tricky in general. Perhaps you don’t truly need SSL? Most SSL-secured things are also available without SSL on localhost domain. Failing that, Caddy is probably easiest. See also bonus tips under secure servers.
Bonus time: tunneling
ngrok is a service that allows you to inspect and replay web service requests from the internet to a local server for analysis.