Clickbait is a form of false advertisement which uses hyperlink text or a thumbnail link that is designed to attract attention and entice users to follow that link and read, view, or listen to the linked piece of online content, with a defining characteristic of being deceptive, typically sensationalized or misleading.^[2][3] A "teaser" aims to exploit the "curiosity gap", providing just enough information to make readers of news websites curious, but not enough to satisfy their curiosity without clicking through to the linked content. Click-bait headlines add an element of dishonesty, using enticements that do not accurately reflect the content being delivered.^[4][5][6] The "-bait" part of the term is used in analogy to fishing, where a hook is disguised by an enticement (bait), presenting the impression to the fish that it is a desirable thing to swallow.

Long before the internet, there was the unscrupulous marketing practice known as bait-and-switch, using similar dishonest methods to hook customers. Like bait-and-switch, clickbait is a form of fraud. (Click fraud, however, is a separate form of online misrepresentation which uses a more extreme disconnect between what is being presented in the frontside of the link versus what is on the click-through side of the link, also encompassing malicious code.) The term 'clickbait' does not encompass all cases where the user arrives at a destination that is not anticipated from the link that is clicked. When the manipulation is done for the purpose of humor, as with rickrolling, and there is no element of exploitation, then that deception does not qualify as clickbait. The term can also be misused when viewers complain about a thumbnail or title that is extremely enticing, as with a sexually provocative image. But if the image or title accurately reflects the content delivered upon click-through, then this is an example of simple enticement. Without the element of deception, it does not qualify as clickbait. The borderline cases happen when a content creator inserts a very short segment in order to serve as justification for a provocative thumbnail, when the vast majority of the content has nothing to do with this short segment or thumbnail. Here, a strong case for clickbait can be made, as the overriding characteristic is deception for the purpose of exploiting the user.

A defining characteristic of clickbait is misrepresentation in the enticement presented to the user to manipulate them to click onto a link.

While there is no universally agreed-upon definition of clickbait, Merriam-Webster defines clickbait as "something designed to make readers want to click on a hyperlink, especially when the link leads to content of dubious value or interest."^[7] Dictionary.com is straightforward in stating that clickbait is "a sensationalized headline or piece of text on the Internet designed to entice people to follow a link to an article on another web page."^[8]

BuzzFeed editor Ben Smith states that his publication doesn't do clickbait, using a strict definition of clickbait as a headline that is dishonest about the content of the article. Smith notes that Buzzfeed headlines such as "A 5-Year-Old Girl Raised Enough Money To Take Her Father Who Has Terminal Cancer To Disney World" deliver exactly what the headline promises. The fact that the headline is written to be eye-catching is irrelevant in Smith's view since the headline accurately describes the article.^[9]

Facebook, while trying to reduce the amount of clickbait shown to users, defined the term as a headline that encourages users to click, but doesn't tell them what they will see.

However, this definition excludes a lot of content that is generally regarded as clickbait.^[3]

A more commonly used definition is a headline that intentionally over-promises and under-delivers.^[10] The articles associated with such headlines often are unoriginal, and either merely restate the headline, or copies content from a more genuine news source.

The term clickbait is sometimes used for any article that is unflattering to a person.

In such cases, the article is not actually clickbait by any legitimate definition of the term.^[11]

From a historical perspective, the techniques employed by clickbait authors can be considered derivative of yellow journalism, which presented little or no legitimate well-researched news and instead used eye-catching headlines that included exaggerations of news events, scandal-mongering, or sensationalism.^[12][13] One cause of such sensational stories is the controversial practice called checkbook journalism, where news reporters pay sources for their information without verifying its truth. In the U.S. it is generally considered an unethical practice, as it often turns celebrities and politicians into lucrative targets of unproven allegations.^[14] According to Washington Post writer Howard Kurtz, "this thriving tabloid culture has erased the old definitions of news by including tawdry and sensational stories about celebrities for the sake of profit."^[14]

For sites that thrive on thousands of click-throughs to content, many authors see the use of clickbait as a means to tap into human psyche by crafting these eye-catching headlines.^[15] There are also those who use this method for phishing attacks for the purpose of spreading malicious files or stealing user information.^[16] The attack occurs once the user opens the link provided to learn more. Clickbait has also been used for political ends and has been blamed for the rise of post-truth politics. Katherine Viner, editor-in-chief at The Guardian wrote that "chasing down cheap clicks at the expense of accuracy and veracity" undermined the value of journalism and truth.^[17] Emotional subjects with stark headlines are widely shared and clicked, which resulted in what Slate described as an "aggregation of outrage" and a proliferation of websites across the political spectrum – including Breitbart News, Huffington Post, Salon, Townhall and the Gawker Media blogs – which profited by producing shareable short-form pieces offering simple moral judgements on political and cultural issues.^[18]

There are various clickbait strategies, including the composition of headlines of news and online articles that build suspense and sensation, luring and teasing users to click.^[19] Some of the popular approaches in achieving these include the presentation of link and images that are interesting to the user, exploiting curiosity related to greed or prurient interest.^[16]]]]]*t is not uncommon, for instance, for these contents to include lewd image or a "make money quick" scheme.

By 2014, the ubiquity of clickbait on the web had begun to lead to a backlash against its use.^[6][20] Satirical newspaper The Onion launched a new website, ClickHole, that parodied clickbait websites such as Upworthy and BuzzFeed,^[21] and in August 2014, Facebook announced that it was taking technical measures to reduce the impact of clickbait on its social network,^[22][23][24] using, among other cues, the time spent by the user on visiting the linked page as a way of distinguishing clickbait from other types of content.^[25] Ad blockers and a general fall in advertising clicks also affected the clickbait model, as websites moved toward sponsored advertising and native advertising where the content of the article was more important than the click-rate.^[18]

As problem attracted interest, tools have been developed to address the clickbait problem.

Clickbait detection, for instance, has been integrated in browser applications while digital platforms where contents are shared such as Twitter have updated their respective algorithms to filter clickbait contents.^[26] Social media groups, such as Stop Clickbait,^{[27][28][29][30]} combat clickbait by giving a short summary of the clickbait article, closing the "curiosity gap". Clickbait reporting browser plug-ins^[31] have been also developed by the research community in order to report clickbait links for further advances in the field based on supervised learning algorithms.