FWIW if I were to do this I'd do

echo <input id=kmbefore><input id=kmafter onleave='alert( (kmafter.value - kmbefore.value) * priceperlitterperkm )'>

> index.html to make it available to anyone, Worldwide, for free!

For the fancy version I'd make priceperlitterperkm URL parameter to make it work not just for my area. But that's like an entire additional like of code.

My point being... I'd make a Web page, on app, no deployment, no tracking.

PS : echo "blabla" > index.html is actually becoming my new World reaching publishing method. I do have a home server with a Web server. I connect to it via ssh keys... so

ssh homeserver 'echo hi >> /var/www/self-published/index.html' and voila. I'll probably share my gist this way from the CLI.

ssh homeserver "echo '$(ls)' >> /var/www/self-published/index.html" if I want to run a command locally first, not on homeserver (notice the " vs ').

  echo <input id=kmbefore><input id=kmafter onleave='alert( (kmafter.value - kmbefore.value) * priceperlitterperkm )'>

 > index.html to make it available to anyone, Worldwide, for free!
You are conveniently leaving out that you already must have:

* a server running 24/7 on the internet, paid for each month

* purchased, setup and keep paying every year a domain name

* configured a web server in that server, ideally with automated SSL certificate issue and renewal

Well yes I'm indeed assuming that you have :

- a place with electricity

- an Internet connection

- a computer, no matter how small (it can literally be a-cig)

which isn't true for literally every one but clearly for OP was.

You don't need a server in the cloud though, like I said a home server is enough.

That, or know that https://neocities.org/ exists.

Or just use GitHub pages.

The article mentions that was proposed and no one wanted to do it.

Also, alerts are terrible UX. At least put some effort into your example.

My point was precisely that no effort was needed to be usable, not that it was perfect. It's taking me longer to argue with you than making it. Again that was the point. We can endlessly make it slightly better... but then we forget why we did this in the first place, namely basic arithmetic for a dozen of people.