Bilibili (stylized as bilibili, Chinese: 哔哩哔哩; pinyin: bīlībīlī; nicknamed B站, literally "the B site", NASDAQ: BILI) is a video sharing website themed around anime, manga, and game fandom (ACG) based in China, where users can submit, view, and add commentary subtitles on videos. Bilibili uses an Adobe Flash or HTML5 player, which can be manually switched, to play user submitted videos hosted by either itself or third-party sources, while featuring a real-time overlaying subtitle system for interactive playback experience.
With the fast growing number of visitors on Bilibili, it decided to expand their functions. Besides the dominant themes, now Bilibili offers videos of various fields, including music, dancing, science and technology, entertainment, movie, drama, fashion, daily life and even advertisement films. Also Bilibili provides a live streaming service where audiences can interact with streamers. Usually the topic is about anime, content creating, game strategy and so on.
Other than videos, Bilibili also offers games, mostly ACG (anime, manga and game) themed mobile games, such as the Chinese version of Fate/Grand Order.
Inspired by similar video sharing websites Nico Nico Douga and AcFun, the founder of Bilibili, Xu Yi (Chinese: 徐逸; pinyin: xúyì, known as "⑨bishi" on the internet), created a prototype website named Mikufans.cn after college graduation in three days. He relaunched the website in January 24, 2010 with the name Bilibili. Later in 2011, he founded a startup, Hangzhou Huandian Technology, to manage the development and operation of Bilibili.
Xu Yi was an AcFun user in 2009. He was unsatisfied by the instability of the service and decided to create an alternative out of fun. He spent three days and created a prototype website named Mikufans.cn as a fandom community of Hatsune Miku. As it grew, he reshaped the website to specialize in video sharing and launched it on January 14, 2010 with the name Bilibili (bilibili.us), which is the nickname of the protagonist Mikoto Misaka in the anime A Certain Scientific Railgun for her electric superpower. Bilibili also names many of its features with reference to this anime, such as to give a "coin" to a user as contribution, which is the reference to Mikoto Misaka's preference to use coins to shoot her electricity. On top of that, Bilibili celebrates Mikoto Misaka's birthday on its homepage every 2 May.
In 2011, Bilibili's domain name bilibili.us was revoked because of the domain registrar enforcing .US restrictions. As a result, Bilibili switched to bilibili.tv on June 25, 2011. Afterwards, in late 2011, Xu Yi founded the startup, Hangzhou Huandian Technology (Chinese: 幻电; pinyin: huàndiàn; literally: "fantastic electricity") based in Hangzhou, Zhejiang, for better development and operation of Bilibili.
In April 2012, Bilibili obtained an agreement with Nico Nico Douga to webcast latest Chinese-subbed episodes of the newly airing anime Fate/Zero starting from April 7. However, this program was censored and ordered to stop after three episodes, for being reported as unauthorized operation of Internet audio-video broadcasting services. Its operating company Hangzhou Huandian Technology was administratively penalized and fined 10,000 yuan by local government.
In August 2012, Bilibili started to display logos on its homepage to indicate affiliation with the state-owned Shanghai Media Group and share the use of various content provider licenses in hope to avoid future legal risk. Meanwhile, anonymous visitors to bilibili.tv got redirected to a subdomain of Shanghai Media Group Broad Band subsidiary (bilibili.smgbb.cn).
Besides hosting video content, Bilibili's core feature is a real-time commentary subtitle system that displays user comments as streams of moving subtitles overlaid on the video playback screen, visually resembling a danmaku shooter game. These subtitles are called "danmaku " (Chinese: 弹幕; pinyin: dànmù; literally: "barrage"). Such subtitles are simultaneously broadcast to all viewers in real-time, creating a chat room experience in which users feel like watching and playing together with others. This system offers users various subtitle controls, including style, format, and movement. Users are also fond of creating translated and soramimi subtitles, or special effects with carefully formed subtitles. The site also offers a feature called "advanced subtitles", where users can use ECMAScript-based API to control video playback, dynamically change danmu subtitles and draw shapes onto the screen. This functionality is only available with the video poster's permission.
Bullet comments are easy to post. User just need to write their thoughts in the type bar under the video, and these comments will show up on the video, usually moving from right to left. If viewers don’t want to be distracted by bullet comments, they can turn it off anytime easily. There are three types of bullet comments offered in Bilibili, rolling comments, top comments and bottom comments. For non-registered visitors, they are able to post either small or medium size bullet comments. Each comment is limited to 20 characters and visitors cannot comment the normal comment page(located below the video). For normal registered users, they are free to choose bullet comments from small to big size, limited of 220 characters. Also they can change the color of the bullet comments and they can comment on the video’s actual comment page. For “professional” bullet comment users, they can choose “extra small” and “extra big” bullet comment. They can also choose to move the comment from left to right (normally it goes from right to left). The blogger of the video has the right to clear or save all bullet comments.
Some people find it annoying to watch a video with bullet comments all over the screen because there are so much that they can’t even watch the actual video. With some heat video like Sherlock, there are more than 8,000 bullet comment. But people also argue that bullet comment allows users to share opinion and draw discussion easily, which creates a unique chat-room environment that makes viewer feel like they are watching the video with the whole world. Bullet comments become a special culture and language in Bilibili. One commonly seen is "high energy alert" (高能預警), which is a kind of spoiler, to tell audience the coming climax or something exciting, terrible scenes.
However, The ministry of culture of China criticized bullet comment for allowing and spreading vicious comments in the video. Therefore, they will keep an eye on the bullet-comment system and they will try everything to stop spreading negative energy on internet.
Bilibili also has an API, enabling third-party developers to access website content including video lists, comments, "danmaku" subtitles, special topics and airing programs. The API service is open for signing up. It is rate-limited and requires developer keys for authentication.
Bilibili's operating company consists of a team of nine members all versed in the Japanese language and culture. Two are web developers, including Xu Yi himself, and the rest are website editors and moderators. Bilibili's service is completely free. Its main revenue comes from webpage advertisement and affiliate marketing.
Bilibili is not open for one minute registration like others, but does not usually require payment. Most content on Bilibili is free for anonymous viewing, while some are member-only to avoid censorship. Membership is required for submitting videos or comments. Bilibili limits membership availability to balance the quality of its user base and moderation capacity. Opportunity of signing up is available occasionally. Starting from March, 2013, the website is open for signing up with a limited number of invitation codes sent by existing users. After registration, users need to complete a 100 question examination to become a premium member, with questions that cover mostly ACG areas. The level of difficulty is so high that users call it "The Chinese Otaku High-school Exam". After 19 May 2015, Bilibili lowered the difficulty to 50 questions, with 20 consisting of proper manner of commentary posting, and 30 knowledge questions on areas of choice. After 26 February 2017, Bilibili restarted its 100 question exam.
It relies on user-submitted posts which reference videos from third-party sources, such as Sina, letv, Youku, and in recent years, many Bilibili users posting YouTube videos to Bilibili. Thus, it risks of being blocked from the sources as it grows large enough to become a burden. Even though its community has been resilient, it has difficulty in maintaining content availability and managing copyright infringement. Bilibili had success in negotiating with Japanese anime companies for licensed webcast, as mentioned above.
The Chinese government has stringent regulations and censorship on Internet services, particularly on Internet video services like Bilibili. Incomplete licenses or insufficient censorship compliance may be serious enough threats to shut down the entire operation of Bilibili if its legal defense is underprepared.
Bilibili has also established affiliated communities: Corari (Chinese: 协作乡; literally: "Hometown of Collaboration", currently offline), a collaboration project founding community; DrawYoo, a creative drawing community; The Ninth Channel, a support forum for Bilibili.
As of 2015, Bilibili has over 50 million users, with 75% of them under the age of 24.
In October 2016, Bilibili announced that they have sponsored Shanghai Sharks of China Basketball Association (CBA) owned by Yao Ming. Bilibili chose Shanghai Sharks as its sponsoring subject due to they both originated from Shanghai that makes it a reasonable cooperation. It was Bilibili's first time to step into the Sports industry as well as bring ACG culture combined with basketball which attracts the younger generation's attention towards sports and sets up a brand new image for basketball industry.
In December 2017, Bilibili purchased an E-sports team originally called IM for League of Legends and it was renamed as Bilibili Gaming(BLG for abbreviation). BLG acted as a brand new team to play in the Tencent League of Legends Pro League (LPL) in China since S8 sports competition season of League of Legends World Championship(LOLWC).
In January 2018, Bilibili purchased broadcast right and right-on-request for spring competition season of LPL, LOLWC, and League of Legends Rift Rivals  of S8. Hereto, Bilibili moved forward to establish an overall distribution of "broadcast-teams-offline sports events" in the sports industry.
The first time Bilibili cooperated with the biggest Chinese online shopping website Taobao was in December 2014 that prepared a special interactive event with its users for the 12th December Online Shopping Festival. Bilibili's logo appeared on the Taobao's front page. Users could shoot danmaku to express their ideas. According to people concerned, Bilibili's staff had already entered and been stationed in Taobao Project office for further operations. It is a great innovation as a combination of different digital brands and is going to be developed more functions further depended on this cooperation relationship.
On 13th March 2015, Durex released a longest-ever online advertisement on Bilibili website, which was last for 3 hours. The advertisement was aimed at White Day. The advertisement campaign was shoot for promoting the new product Durex Air and its concept supermarket idea, which attracted 100 million audiences watched it online and sent their comments by danmaku. It is a new kind of creative digital marketing method acting as a performance art that satisfies young people's curiosity.
On 10th May 2015, Xiaomi held a product launch for its new series Xiaomi Max. During the conference, Bilibili acted as its live broadcast platform that was last for 19 days. The audience totally reached 39.54 million during the period and comments on it broke through 3.17 billion. The broadcast was to test and demonstrate the battery life of Xiaom Max through checking the smartphone once an hour to see if it was still powered on. Although it was thought to be a most boring ever live show, still, many audiences kept watching it still the end of the broadcast. It is a cooperation between an online and offline brand that makes different marketing tools integrated to bring along a most effective marketing and advertising campaign.
另外，本次為了造福中國地區的粉絲，也確定在中國動畫網站『嗶哩嗶哩動畫』進行《Fate/Zero》第２季簡體中文字幕網路同步播出！(Besides, for the enjoyment of fans in China at this time, we decided to webcast Fate/Zero the second season with simplified Chinese subtitle on the Chinese anime website "Bilibili Donghua" at the same time!)