A webmaster is a person who builds, maintains, and takes responsibility for a website. The term fell out of fashion as the role fragmented into specialists, and it is being reclaimed by the independent web as a name for anyone who runs their own site.
Adapted from WEBMASTER@ a manifesto for everyone on brennan.day.
The role descends from the postmaster, the email administrator defined in early Internet specifications. RFC 2142 (1997) reserved webmaster@domain as a contact address the way postmaster@domain was already reserved. The first webmaster was a woman: Louise Addis ran the SLAC website from 1993, on the first web server outside CERN.
From roughly 1994 to 2001, the webmaster was the generalist of the early web: designer, developer, and administrator in one, hand-coding HTML, FTPing files, and answering mail. Free hosts like GeoCities made the role accessible, and the “under construction” sign captured an honest truth: the web is perpetually under construction. See Cybercultural's GeoCities history and Olia Lialina's GeoCities' Afterlife and Web History.
Between roughly 2008 and 2020 the role was split into UX designers, frontend developers, content managers, and SEO specialists, and the term was left behind. Google retired “Google Webmasters” for “Search Central” in 2020. Jay Hoffman's What Happened to the Webmaster tracks the term's rise and fall; Brian Wold's rebuttal describes the original figure.
The independent web uses “webmaster” to mean what it always meant: the person responsible for a site. No credentials required. The communities where the title lives on: 32-bit Cafe forums, IndieWeb IRC, Neocities, Nekoweb, and web 1.0 hosting. See Web 1.0 Aesthetics and Independent Platforms.