Mosaic makes the web visual
A free browser from a university supercomputing center puts pictures on the same page as text
Quick facts
- Creators
- Marc Andreessen and Eric Bina, NCSA, University of Illinois
- First release
- January 1993
- Key innovation
- Inline images shown with text on the same page
- Later company
- Mosaic Communications, renamed Netscape
What happened
Marc Andreessen and Eric Bina, programmers at the National Center for Supercomputing Applications (NCSA) at the University of Illinois, built Mosaic, a browser released as an early version in January 1993 and as version 1.0 that April, with Windows and Macintosh versions following that September. It was the first widely used browser to display images inline on the same page as text, rather than as separate windows or plain text placeholders, arranging pictures and words the way a printed magazine layout would. By December 1993, more than 5,000 copies were being downloaded every month, and the New York Times called it network computing's first 'killer app,' a program so useful on its own that it could create an entire new industry from nothing.
Why it matters
Berners-Lee's original web software worked, but Mosaic made it visual and easy enough for non-technical people to want to use, turning the web from a tool for physicists and researchers into something a much broader public would adopt within a few years. Andreessen left NCSA to found Mosaic Communications, later renamed Netscape, carrying the browser's lineage directly into the first browser wars.
How we know
The University of Illinois's own NCSA page documents Andreessen and Bina's roles, the inline-image innovation, and the download numbers that made Mosaic the web's first mass-adopted browser.
Sources
- National Center for Supercomputing Applications, University of Illinois. NCSA Mosaic · Reputable sourcencsa.illinois.edu · The domain "ncsa.illinois.edu" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
- Computer History Museum (CHM Revolution). Marc Andreessen · Reputable sourcecomputerhistory.org · The domain "computerhistory.org" is on our Reputable source registry.
See something wrong? . Corrections with a source get fixed fastest.
Part of a timelineThe Internet and Computing36 events · From a mechanical engine that never ran to a network that never sleepsView all →