As of April 2015, the most popular sites for watching free full movies online are Crackle.com, Hulu.com, Popcornflix.com and Yidio.com. Of these options, Crackle provides the largest library of free content, supported by occasional advertisements.
While all of the websites mentioned above offer free full movie streams, they are ad-supported, meaning that viewers will be periodically shown advertisements mid-film from companies the websites have partnered with. Viewers who want to remove advertisements and gain access to higher quality streams are often required to purchase a paid subscription. Hulu, for example, offers free standard definition movies to registered users, while providing high definition and Blu-Ray quality movies to paying subscribers.
Each of these websites offer viewers a choice between different films based on the production companies they have partnered with: Crackle.com has partnered with Sony Pictures, while Hulu has exclusive rights to Miramax films and classics in the Criterion Collection. Popcornflix gets its films from Screen Media Ventures, a large independent distributor not exclusively affiliated with any single film production company. Yidio purchases rights for movie streaming on its own platform, and also hosts numerous links to films provided by other movie streaming websites, including Crackle and Hulu. Since these websites have purchased streaming rights for their films, they are completely legal to use.