Andreessen said that in 1992 he was asked to implement a nudity filter.

True: contemporaneous or reliable historical evidence (Mosaic/NCSA history, interviews, accounts by colleagues) shows Andreessen was asked to implement a nudity or content filter in a web browser he worked on, with the request made in 1992. Mostly true: the request happened, but in a nearby year (e.g. 1993, when Mosaic was being developed) or in a slightly different context. Mixed: evidence confirms related content-filtering requests but not one made to Andreessen specifically. Mostly false: the story rests on something real but the key details are distorted. False: reliable evidence contradicts it, for example by showing no such request could have been made at that time. If the only source is Andreessen's own account, treat it as unverified and do not rate above mostly true.

Set before the research began.

1. E1 NCSA Mosaic: what happened, and why it shut down | Looks Back Looks Back · 13 August 2026

   “Development began at the National Center for Supercomputing Applications, at the University of Illinois, in December 1992, and the first release came in January 1993. Marc Andreessen and Eric Bina wrote it.”

2. E2 The Making of Netscape - Columbia Business School Columbia Business School (case by Professor Rajeev Kohli) · 11 July 2026

   “Marc Andreessen started working on the Mosaic web browser in 1992.”

3. E3 Netscape's Navigator National Museum of American History, Smithsonian Institution · June 1995 Own record

   “I came back from IBM and joined NCSA largely because they were doing a lot of 3D work.”

4. E4 The Making of the World Wide Web Freie Universität Berlin (course text)

   “Marc Andreessen was a student and part-time assistant at the National Center for Supercomputing Applications (NCSA) at the University of Illinois, when he first came into contact with the World Wide Web.”

5. E5 The Making of Netscape Columbia Business School (Prof. Rajeev Kohli, case study)

   “Marc Andreessen started working on the Mosaic web browser in 1992. He was a computer science student at the University of Illinois”

6. E6 The Making of Netscape Columbia Business School (Prof. Rajeev Kohli, case study)

   “Mosaic was introduced in March 1993. It rapidly gained users.”

7. E7 How Netscape Navigator Won and Then Lost the World Wide Web Popular Mechanics · 4 April 2019

   “In 1992, Andreessen was a gifted Unix coder making $6.85 an hour at the university’s National Center for Supercomputing Applications.”

8. E8 NCSA Mosaic - Wikipedia Wikipedia · 7 March 2002

   “Mosaic was developed at the National Center for Supercomputing Applications (NCSA)[7] at the University of Illinois at Urbana–Champaign beginning in December 1992[10], released in January 1993,[11]”

9. E9 NCSA Mosaic - Wikipedia Wikipedia · 7 March 2002

   “Andreessen and Bina began developing Mosaic in February 1991 for Unix's X Window System, calling it xmosaic.”

10. E10 A Little History of the World Wide Web World Wide Web Consortium (W3C) · 28 October 2026

    “Project Page as of 3 Nov 1992 and the WWW project web of the time,”

Independent sources place Andreessen at NCSA in 1992 (E7) and date the start of his work on Mosaic to 1992 (E2, E5), with E1 and E8 giving December 1992, though E9 gives February 1991. None of the evidence mentions anyone asking Andreessen, or anyone else, to build a nudity or content filter. The evidence shows such a request was possible at that time but does not confirm or contradict it. Even Andreessen's own account is not among the evidence items.