The first widely used graphical web browser was Mosaic, formally known as NCSA Mosaic. Developed at the National Center for Supercomputing Applications at the University of Illinois, Mosaic helped transform the web from a specialist tool into a medium accessible to a much broader public.
Mosaic was released in 1993. It was not the first web browser: Tim Berners-Lee’s WorldWideWeb and several other early browsers came before it. Mosaic’s breakthrough was its polished, approachable interface and its ability to display images inline with text, rather than opening them in a separate window.
The browser also supported multiple internet protocols, including HTTP, FTP, Gopher, and NNTP. Its ease of installation and availability on popular computer platforms helped drive rapid web adoption. Several members of the Mosaic team later influenced commercial browser development, including the creation of Netscape Navigator.
Firefox and Internet Explorer became important much later. Netscape Navigator was Mosaic’s successor in the browser market’s early commercial era, but Mosaic is the canonical answer to the question of which browser first made graphical web browsing widely popular.