TikTok is an iOS and Android social media video app for creating and sharing short lip-sync, comedy, and talent videos. The app was launched in 2017 by ByteDance, for markets outside of China. ByteDance has previously launched Douyin (Chinese: 抖音) for the China market in September 2016.

TikTok and Douyin are the same, but run on different servers to comply with Chinese censorship restrictions. The application allows users to create short music and lip-sync videos of 3 to 15 seconds^[4][5] and short looping videos of 3 to 60 seconds. It is popular in Asia, United States, and other parts of the world.^[6] TikTok is not available in China and its servers are based in countries where the app is available.^[7]

In 2018, the application gained popularity and became the most downloaded app in the U.S. in October 2018.^[8][9] As of 2018, it is available in over 150 markets, and in 75 languages. In February 2019, TikTok, together with Douyin, hit one billion downloads globally, excluding Android installs in China.^[10]

Douyin was launched by ByteDance in China in September 2016.^[11] Douyin was developed in 200 days, and within a year got 100 million users, with more than 1 billion videos viewed every day.^[9][13] TikTok was launched in the international market in September 2017.^[8] On 23 January 2018, the TikTok app ranked #1 among free mobile app downloads on app stores in Thailand and other countries.^[15]

TikTok has been downloaded about 80 million times in the United States, and 800 million times worldwide, according to data from mobile research firm Sensor Tower that excludes Android users in China.^[16] Celebrities including Jimmy Fallon and Tony Hawk have joined the app in November 2018.^[17][18]

On September 3, 2019, TikTok and the NFL announced a multi-year partnership. The partnership includes the launch of an official NFL account that will bring NFL content to worldwide fans.^[19]

On 9 November 2017, TikTok's parent company, ByteDance, spent up to $1 billion to purchase musical.ly, a startup based in Shanghai with an office in Santa Monica, California, owning a popular social media platform targeting the US teenage market.^[20][21] Looking forward to leveraging the US digital platform's young user base, TikTok merged with musical.ly on 2 August 2018 to create a larger video community, with existing accounts and data consolidated into one app, keeping the title TikTok.^[21][22][23] Musical.ly was a social media video platform that allowed users to create short lip-sync and comedy videos. Its official release was on August 2014.

As of 2018, TikTok is now available in over 150 markets, and in 75 languages.^[24][25] TikTok was downloaded more than 104 million times on Apple's App store during the full first half of 2018, according to data provided to CNBC by Sensor Tower, an app analytics platform based in San Francisco. It surpassed Facebook, YouTube and Instagram to become the world's most downloaded iOS app for that time period.^[26][27]

As a separate app from TikTok, Douyin is available from the developer's website and has maintained the same app title since its launch in September 2016.^[28] Part of its popularity is attributable to its marketing campaigns, launching several activities with Chinese celebrities to engage their fans' interest.

For example, its marketing campaign in 2018 Spring Festival Gala alone brought an increase of 70 million daily active users.^[29] In February 2018, Douyin launched a partnership with Modern Sky to monetize music.^[30]

The TikTok mobile app allows users to create a short video of themselves which often feature music in the background, can be sped up, slowed down or edited with a filter.^[31] To create a music video with the app, users can choose background music from a wide variety of music genres, edit with a filter and record a 15-second video with speed adjustments before uploading it to share with others on TikTok or other social platforms.^[32] They can also film short lip-sync videos to popular songs.

The app's "react" feature allows users to film their reaction to a specific video, over which it is placed in a small window that is movable around the screen.^[33] Its "duet" feature allows users to film a video aside another video.^[34] The “duet” feature was another trademark of musical.ly

The app allows users to set their accounts as "private".

Such accounts' content remains visible to TikTok, but is blocked from TikTok users who the account holder has not authorised to view their content.^[35] Users can choose whether any other user, or only their "friends", may interact with them through the app via comments, messages, or "react" or "duet" videos.^[33][35] Users also can set specific videos to either “public”, “friends only”, or “private” regardless if the account is private or not.

The “for you” page on TikTok is a feed of recommended videos to you based on your previous actions on the app, consisting of what kind of content you've liked.

Users can only be featured on the “for you” page if they are 16 or over per TikTok policy.

Users under 16 will not show up under the “for you” page, under sounds, or under any hashtags.^[36]

You can also add videos, hashtags, filters, and sounds you like to your “saved” section.

This section shows on your profile (only visible to you) allowing you to refer back to any video, hashtag, filter, or sound you've previously saved.

TikTok employs artificial intelligence to analyse users' interests and preferences through their interactions with the content, and display a personalized content feed to each user.^[37][38]

TikTok became the world's most downloaded app on Apple's App Store in the first half of 2018 with an estimated 104 million downloads, surpassing the downloads recorded by PUBG Mobile, YouTube, WhatsApp and Instagram in the same period.^[26] Studies have shown that in just one year, short videos in China have gone up by 94.79 million. ^[39]

The app has spawned numerous viral trends and internet celebrities around the world, propelled songs to fame, and is known to be popular among celebrities due to its popularity and social influence.^{[40][41][42][43][44][45]} The most well-known viral TikTok meme in the Western world is "hit or miss", from a snippet of iLOVEFRiDAY's "Mia Khalifa" (2018), which has been used in over four million TikTok videos, and helped introduce TikTok to a larger Western audience.^[46] The platform has received some criticism, however, for its lack of royalties towards artists whose music is used on their platform.^[46]

Similar to other platforms,^[47] journalists in several countries have raised privacy concerns about the app, not least because it is popular with children and may expose them to sexual predators.^{[47][48][49][50]}

Several users have reported endemic cyberbullying on TikTok,^[51][52] including racist abuse.^[53]

Some users may find it hard to stop using TikTok.^[54] In April 2018, an addiction-reduction feature was added to Douyin.^[54] This encourages users to take a break every 90 minutes.^[54] Later in 2018, the feature was rolled out to the TikTok app.

In January 2019, an investigation by the American think tank Peterson Institute for International Economics described TikTok as a "Huawei-sized problem" that poses a national security threat to the West,^[55][56][57] noting the app's popularity with Western users including armed forces personnel, and its ability to convey location, image and biometric data to its Chinese parent company, which its legally unable to refuse to share data with the Chinese government.^[56][57]

Observers have also noted that ByteDance's founder and CEO Zhang Yiming issued a letter in 2018 stating that his company would "further deepen cooperation" with Communist Party of China authorities to promote their policies.^[58] TikTok's parent company ByteDance claims that TikTok is not available in China and its data is stored outside of China, but its privacy policy has reserved the right to share any information with Chinese authorities.^[59]

On 3 July 2018, TikTok was banned in Indonesia, after the Indonesian government accused it of promulgating "pornography, inappropriate content and blasphemy."^{[60][61][62][58][63]} Shortly afterwards, TikTok pledged to task 20 staff with censoring TikTok content in Indonesia,^[61] and the ban was lifted on 11 July 2018.^[60]

In November 2018, the Bangladeshi government blocked the TikTok app's internet access.^[64] Also in 2018, Douyin was reprimanded by Chinese media watchdogs for showing "unacceptable" content, such as videos depicting adolescent pregnancies.^[63]

In January 2019, the Chinese government said that it would start to hold app developers like ByteDance responsible for user content shared via apps such as Douyin,^[65] and listed 100 types of content that the Chinese government would censor.^[66][67] It was reported that certain content unfavorable to the Communist Party of China has already been limited for users outside of China such as content related to the 2019 Hong Kong protests.^[68] TikTok's policies also ban content related to a specific list of foreign leaders such as Vladimir Putin, Donald Trump, Barack Obama, and Mahatma Gandhi.^[69]

In February 2019, several Indian politicians called for TikTok to be banned or more tightly regulated, after concerns emerged about sexually explicit content, cyberbullying, and deepfakes.^[70]

In September 2019, The Guardian revealed that TikTok instructs its moderators to censor videos that mention Tiananmen Square, Tibetan independence and the religious group Falun Gong.

According to leaked documents detailing the site’s moderation guidelines, the censored content covers “demonisation or distortion of local or other countries’ history such as May 1998 riots of Indonesia, Cambodian genocide, Tiananmen Square incidents”.

TikTok moderators have banned content that could be perceived as being positive towards to gay people or gay rights, including same-sex couples holding hands, including in countries where homosexuality has never been illegal.^[69]

There are a variety of trends within TikTok, including memes, lip-synced songs, and comedies.

Duets, a feature that allows users to add their own video to an existing video with the original content's audio, have led to most of these trends.

Trends are shown on the explore page on TikTok, or the page with the search logo.

The page enlists the trending hashtags and challenges among the app.

Some include #posechallenge, #filterswitch, #makeeverysecondcount, #wannalisten, #pillowchallenge, #furrywar, #hitormiss, #bottlecapchallenge and more.

In June 2019, the company introduced the hash tag #Edutok which received 37 billion views.

Following this development the company initiated partnerships with Edtech start ups to create educational content on the platform.^[72]

This list contains the top 10 accounts that had the most followers on Douyin, which is the Chinese version of TikTok and mostly used in China.^[73]

Indonesia temporarily blocked the TikTok app on 3 July 2018 amid public concern about illegal contents such as pornography and blasphemy. The app was unblocked one week later after making various changes, including removing negative content, opening a government liaison office, and implementing age restrictions and security mechanisms.^[74]

Tencent's WeChat platform has been accused of blocking Douyin's videos.^[75][76] In April 2018, Douyin sued Tencent and accused it of spreading false and damaging information on its WeChat platform, demanding RMB 1 million in compensation and an apology. In June 2018, Tencent filed a lawsuit against Toutiao and Douyin in a Beijing court, alleging they had repeatedly defamed Tencent with negative news and damaged its reputation, seeking a nominal sum of RMB 1 in compensation and a public apology.^[77] In response, Toutiao filed a complaint the following day against Tencent for allegedly unfair competition and asking for RMB 90 million in economic losses.^[78]

On 27 February 2019, the United States Federal Trade Commission fined ByteDance US$5.7 million for collecting information from minors under the age of 13 in violation of the Children's Online Privacy Protection Act.^[79] ByteDance responded by adding a kids-only mode to TikTok which blocks the upload of videos, the building of user profiles, direct messaging, and commenting on other's videos, while still allowing the viewing and recording of content.^[80]

On 3 April 2019, the Madras High Court while hearing a PIL had asked the Government of India to ban the app, citing that it "encourages pornography". The court also noted that children using the app were at risk of being targeted by sexual predators. The court further asked broadcast media not to telecast any of those videos from the app. The spokesperson for TikTok stated that they were abiding by local laws and were awaiting the copy of the court order before they take action.^[81] On 17 April, both Google and Apple removed TikTok from Google Play and the App Store.^[82] As the court refused to reconsider the ban, the company stated that they had removed over 6 million videos that violated their content policy and guidelines.^[83]

On 25 April 2019, the ban was lifted after a court in Tamil Nadu reversed its order of prohibiting downloads of the app from the App Store and Google Play, following a plea from TikTok developer Bytedance Technology.^[84][85] India's TikTok ban might have cost the app 15 million new users.^[86]