Many of the films in the Star Wars franchise have been re-released, both theatrically and on home media formats. Franchise creator George Lucas often altered the films for the re-releases. These alterations range from minor refinements (such as color grading and audio mixing) to major changes (such as the insertion of new dialogue, characters, and visual effects). The original trilogy was altered the most, although revisions were also made to the prequels. According to Lucas, some changes brought the films closer to his original vision, while others were attempts to create continuity with later films.
While different versions of the Star Wars films have existed since the 1977 release of the original film (later titled A New Hope), the first major changes were made in 1997 for the release of a Special Edition remaster in commemoration of the franchise's 20th anniversary. These changes were largely made as visual effects tests for the forthcoming prequel films, demonstrating the possibilities of computer-generated imagery (CGI). Additional notable changes were made when the original trilogy was released on DVD in 2004, in an attempt to create more consistency with the prequel trilogy. More changes were made to the films for their Blu-ray release in 2011 and for their 4K Ultra HD release in 2019.
Although some fans and critics felt that many of the smaller changes were innocuous or justified, most larger changes were received negatively—particularly those made to the original three films, the theatrical versions of which have never been officially released in high definition. Although the master negatives of the original trilogy were dismantled, another set of high-quality duplicates was created for long-term preservation.