According to Wikipedia [1], the term was coined by American white nationalist Richard B. Spencer and shortened to "alt-right" and popularised by far-right participants of /pol/, the politics board of web forum 4chan.

So more a label that they slapped on themselves.

[1] https://en.wikipedia.org/wiki/Alt-right

That Wikipedia article seems like a stretch?

A white nationalist launched a webzine called “The Alternative Right”.

Then “His term was shortened to "alt-right" and popularised by far-right participants of /pol/, the politics board of web forum 4chan.”

So other people used the term alt-right and somehow it’s linked to a webzine?

You could always correct that article then.

I could, but I like my sanity!

But anyways, thanks for the link, I wasn't aware that at least wikipedia makes that connection. I've alway heard "alt-right" used as "a vague collection of far right people that fall outside the Republican Party". So they could include white supremacists, but aren't exclusively white supremacists.