The power of Hashtags

Twitter, Facebook, Instagram, Tumblr, Pinterest, Google Plus, and many others: social networks that use hashtags as a connection tool between users’ content are now many, to the point that the typical “hash” – like the “at” @ – has been transformed into a hallmark of online communication. But who invented the hashtags and made them famous on the web?

What are hashtags? Hashtags are a kind of label that social media users put into their content to make it easily traceable. Every hashtag corresponds to a particular topic and is composed of the character # (hash or pound sign or number sign) next to the keyword chosen to become the label: for example #indoona. The presence of the hash, in fact, turns the word into a real link to all posts and threads where that hashtag has been inserted. This way we can easily group in a list thousands of content on a single topic.

The first social network to use hashtags was Twitter and its system it has long been one of its most important features, not only to “sort” posts threads, but also to determine their degree of popularity. However, on its debut, the same “blue bird” social network did not believe particularly in the communicative potential of hashtags: their only feature was to highlight the word marked by the #. It was the digital “guru” Chris Messina, in a 2007 tweet to suggest the use of hashtags to identify a group of topics and to “mint” in this sense the first real hashtag in history: #barcamp. Two months later, the entrepreneur Nate Ritter created from nothing the hashtag #SanDiegoFire to group tweets and news about a terrible fire broke out in the city of San Diego, defining, in fact, a label useful to all those who sought updates about that fire.

Only two years later, however, Twitter enabled the aggregation of tweets by hashtags and their search in the internal search engine. The rest is history: the hashtags have given way to the Trending Topic phenomenon (also localized by country), that are the “hottest topics” of the moment, identified based on the number of related tweets. They are now also used for live coverage of a lot of events or to carry on civil rights battles – for example the hashtag #OccupyGezi, used during the 2013 protests in Turkey to defend the freedom of speech and the right to assembly, or #JeSuisCharlie.

After Twitter, also other social networks have realized the power of hashtags and adopted them to aggregate their content: some have been very successful (Instagram, Tumblr), others less (Facebook, Google Plus). What is certain is that now the hashtag is an integral part of the social media universe and, in a landscape of enormously vast content, it is probably the best tool to navigate within it.


A curiosity: the origin of # is not clear, for some it is an ancient abbreviation from the Latin language, capital barred N, used to indicate the word numerus (number), for others it’s an evolution of the symbol , used to indicate the term libra pondo (pound weight). The character was then barred so as not to confuse the lowercase letter “l” with the number 1. As the years passed the symbol would be reduced as an overlay of two horizontal strokes “=” across two forward-slash-like strokes “//”.