This list of most disliked YouTube videos contains the top 40 videos with the most dislikes of all time, as derived from YouTube charts. The dislike count is taken directly from the page of the video itself. YouTube implemented a like and dislike button on these pages in 2010, part of a major redesign of the site. This served as a replacement for their five-star rating system; YouTube's designers found the previous system ineffective because the options to rate a video between two and four stars were rarely selected.
The music video for Justin Bieber's song "Baby" stood as the most disliked video on YouTube in 2011, with 1.17 million dislikes, until the video for Rebecca Black's "Friday" surpassed it in March that year, yielding more than 1.2 million dislikes. "Friday" amassed more than three million dislikes before the video was taken down in June 2011 (before being reinstated three months later). Following this removal, "Baby" entered the Guinness World Records book as the most disliked video on YouTube and on the Internet as of 2013. At over seven million dislikes, Bieber's video remains the most disliked on YouTube as of 2017[update].
Measurement of dislikes on YouTube has been of academic and political interest. Following its immediate negative reception, Rick Perry's advertisement "Strong" was reported to have surpassed "Friday" in number of dislikes, a statistic which went viral. Perry's advertisement was measured against a September 2011 reupload of Black's video, which had been disliked 250 thousand times, much less than before the original upload had been taken down. This incongruity was seen by Mike Barthel of The Village Voice as a reason not to judge online publicity over entertainment and politics by the same metric. In 2015, the dislike button was manipulated by means of proxies by Vietnamese hackers to subvert opinions of a product made in the country. While music videos make up a majority of the most disliked uploads to YouTube, the trailer for the 2016 film Ghostbusters became the most disliked movie trailer on the site, with over 1 million dislikes. Some commentators saw this backlash as a concerted effort to vote the film down into obscurity. Along with the most disliked movie trailer, 2016 showed the most disliked video game trailer, Call of Duty: Infinite Warfare, which stands at over 3 million dislikes. It became YouTube's second most disliked video within two weeks of being released. On Christmas Eve of 2016, the most subscribed YouTuber, PewDiePie, uploaded a video challenging his viewers to make it reach 1 million dislikes. Within four days, the video received over 2.5 million dislikes, quickly becoming the third most disliked video of all time.