The symbol #, known as the hash, pound, or number sign, has been used in various contexts for decades. In North America, it was commonly referred to as the pound sign, used to denote weight in pounds. In the UK, it was often called the hash sign, especially in reference to its use in computing.
In computing, the hash sign was used in programming languages. Its use became more widespread with the advent of touch-tone telephones, where it was used as the pound key. It served various purposes, like indicating the end of a command sequence.
The concept of using the hash sign as a hashtag in social media was proposed by Chris Messina, a product designer, in a tweet on August 23, 2007. He suggested using the hash symbol to group related tweets together. This was initially met with scepticism by Twitter, as they thought it was too technical for the average user.
Despite Twitter's initial reluctance, the use of hashtags began to catch on among users, particularly during significant events like the San Diego forest fires in 2007, where the hashtag #SanDiegoFire was used. This helped users easily follow updates on the event. Seeing its utility in aggregating discussions, Twitter officially adopted hashtags in 2009, with clickable hashtags that led users to a page showing all tweets sharing that hashtag.
Following their success on Twitter, other social media platforms began adopting hashtags. Instagram incorporated them in 2010, followed by Facebook in 2013. Hashtags became a way to connect social media content to specific topics, events, themes, or conversations.
The use of hashtags has transcended social media and entered everyday language. They are used in spoken conversations, often humorously or ironically, and have become significant in digital marketing, activism (e.g., #MeToo, #BlackLivesMatter), and popular culture.
Today, hashtags are a fundamental part of social media, shaping the way information is categorised and discovered online. They allow for the organisation of content, enabling easier discovery of posts and fostering community engagement around shared interests or causes.
