Hashtag

2007Social media convention / metadata tagclassic

Also known as: Hash tag · pound sign tag · # tag

Hashtag is a 2007 social media convention proposed by Chris Messina using # to prefix words or phrases for tagging and organizing posts around shared topics.

A hashtag is a word or phrase prefixed with the # symbol, used on social media to tag and organize posts around a shared topic. First proposed for Twitter by Chris Messina on August 23, 20071, the hashtag grew from a niche convention into one of the most recognizable features of online communication, eventually being named the 2012 Word of the Year by the American Dialect Society2.

TL;DR

A hashtag is a word or phrase prefixed with the # symbol, used on social media to tag and organize posts around a shared topic.

Overview

A hashtag is a metadata label consisting of the # symbol followed by a word or phrase with no spaces. When someone includes a hashtag in a post, it groups that content with every other post using the same tag, making it easy to find and follow conversations about a specific subject3. The format is dead simple: type #, add your keyword, and you've created a searchable link to a broader discussion.

Hashtags are not case-sensitive (#Hashtag and #hashtag return the same results), though CamelCase improves readability3. The convention works across nearly every major social platform today, from X (formerly Twitter) and Instagram to Facebook, YouTube, TikTok, and LinkedIn5.

The # symbol itself has ancient roots. It traces back to the Latin abbreviation *lb* for *libra pondo* ("pound in weight"), which scribes wrote with a horizontal line across to indicate abbreviation. Over centuries of hasty handwriting, that ligature morphed into the # we know today6. The symbol appeared on typewriter keyboards in the 1870s and was added to Bell Labs' touch-tone telephone keypad in 19685.

The practice of using # to organize online discussions started on IRC (Internet Relay Chat) networks around 1988, where chat rooms were prefixed with the symbol followed by a topic name3. But IRC hashtags were limited to people actually in the room.

Chris Messina, a Google user experience designer who earned his communication design degree from Carnegie Mellon in 20037, brought the concept to Twitter. On August 23, 2007, he tweeted: "how do you feel about using # (pound) for groups. As in #barcamp [msg]?"1. Two days later, he published a detailed blog post titled "Groups for Twitter; or A Proposal for Twitter Tag Channels," arguing that the # convention could let Twitter users follow topic-based conversations without needing to follow each other directly8. He cited the March 2007 South by Southwest Interactive conference as an example of where hashtags would have been useful.

On August 28, 2007, web anthropologist Stowe Boyd responded with a blog post where he coined the actual term "hash tag" to describe the concept4. Messina pitched the idea formally to Twitter co-founders Biz Stone and Ev Williams, but they reportedly told him hashtags were "for nerds" and would never catch on5.

Origin & Background

Platform
IRC (original # convention), Twitter (modern hashtag proposal)
Key People
Chris Messina, Stowe Boyd
Date
2007
Year
2007

The # symbol itself has ancient roots. It traces back to the Latin abbreviation *lb* for *libra pondo* ("pound in weight"), which scribes wrote with a horizontal line across to indicate abbreviation. Over centuries of hasty handwriting, that ligature morphed into the # we know today. The symbol appeared on typewriter keyboards in the 1870s and was added to Bell Labs' touch-tone telephone keypad in 1968.

The practice of using # to organize online discussions started on IRC (Internet Relay Chat) networks around 1988, where chat rooms were prefixed with the symbol followed by a topic name. But IRC hashtags were limited to people actually in the room.

Chris Messina, a Google user experience designer who earned his communication design degree from Carnegie Mellon in 2003, brought the concept to Twitter. On August 23, 2007, he tweeted: "how do you feel about using # (pound) for groups. As in #barcamp [msg]?". Two days later, he published a detailed blog post titled "Groups for Twitter; or A Proposal for Twitter Tag Channels," arguing that the # convention could let Twitter users follow topic-based conversations without needing to follow each other directly. He cited the March 2007 South by Southwest Interactive conference as an example of where hashtags would have been useful.

On August 28, 2007, web anthropologist Stowe Boyd responded with a blog post where he coined the actual term "hash tag" to describe the concept. Messina pitched the idea formally to Twitter co-founders Biz Stone and Ev Williams, but they reportedly told him hashtags were "for nerds" and would never catch on.

How It Spread

Despite Twitter's initial indifference, early adopters ran with the idea. In October 2007, Nate Ritter used the hashtag #sandiegofire to post twelve hours of continuous news updates during the Southern California wildfires that burned nearly a million acres across the region. The tag drew attention from news outlets and blogs, proving hashtags could organize real-time information during breaking events.

Not everyone was on board. In a February 2008 blog post, content strategist Dave Coustan announced he would unfollow anyone who used hashtags, arguing they cluttered the conversational feel of Twitter with machine-readable metadata. "I want my Twitter to remain as human a form of communication as possible," he wrote. His stance captured the skepticism some users felt about the format's visual intrusiveness.

That same year, Twitter's mom-blogger community started using hashtags to host virtual parties. By November 2008, bloggers from Mommy Gossip (later Mom It Forward) launched a weekly Tuesday-night "Girls' Night Out" under the hashtag #gno, attracting 250-500 participants sending over 1,500 tweets per hour. Sitewarming parties organized by mommy blogger Amy Bair regularly pushed their hashtags to the top of Twitter Search trending topics within minutes.

In early 2009, how-to guides for using hashtags started appearing on tech blogs like Mashable. Then in April 2009, the format got its first major stress test when Amazon appeared to de-rank LGBT-themed books from search results. The hashtag #AmazonFail spread rapidly across Twitter as users organized collective outrage. NPR covered the backlash, the Wall Street Journal coined it a new term, and internet researcher Clay Shirky published a now-famous analysis calling the hashtag's viral spread both a "failure" and an "intoxicating" experience, noting how the emotional rush of joining a righteous hashtag campaign could override critical thinking.

How to Use This Meme

Hashtags follow a simple format:

1

Type the # symbol followed immediately by your word or phrase (no space between # and the word)

2

No spaces or special characters within the hashtag. Multiple words run together: #ThrowbackThursday, not #Throwback Thursday

3

Keep it concise. #bizducks works better than #businessofthecallingducksconference

4

Give context. If creating a new hashtag, explain what it's for in your first few posts

Cultural Impact

Hashtags fundamentally changed how information spreads online. They gave ordinary users the power to create and join conversations at scale, without needing permission from any platform or gatekeeper.

In marketing, brands built entire campaigns around hashtags. Calvin Klein's #MyCalvins encouraged users to post photos in their underwear. Red Bull's #PutACanOnIt promoted creative photos with their product. Expedia's #ThrowMeBack campaign offered travel vouchers for nostalgic posts. But brand hashtag campaigns also backfired spectacularly at times, as companies discovered they couldn't control how the public would use an open tag.

In politics and social justice, hashtags became organizational tools for real movements. The Arab Spring protests, Occupy Wall Street, Black Lives Matter, and Me Too all used hashtags as rallying points that could spread faster than any traditional organizing method.

Messina, the inventor, never attempted to patent the concept. "They were born of the internet, and owned by no one," he said. He continued working in tech and is recognized by Carnegie Mellon University as a notable alumnus.

Full History

Twitter finally built official support for hashtags on July 2, 2009, hyperlinking all hashtagged words in tweets to search results. This was nearly two years after Messina's original proposal, but it changed everything. In 2010, Twitter introduced "Trending Topics" on its homepage, displaying the most popular hashtags in real-time. The company started selling sponsored trending topics to brands like Disney, Coca-Cola, and Hyatt for a reported $100,000-$120,000 per day. During the 2010 World Cup, Twitter deployed "hashflags" that replaced three-letter country code hashtags with national flags.

The 2009-2010 Iranian election protests marked a turning point for hashtags as tools of political activism. Twitter users employed both English and Persian-language hashtags to coordinate and share information during the events. This set the template for a decade of hashtag activism that would follow.

Other platforms took notice. YouTube began supporting hashtags, and real-time search services like Google Real-Time Search incorporated them. Instagram, which launched in 2010, made hashtags central to content discovery. Posts with at least one Instagram hashtag averaged 12.6% more engagement than those without. Facebook added hashtag support on June 12, 2013, though its implementation was limited by privacy settings. Users could only see public posts and content shared by friends, unlike Twitter's fully open search model. LinkedIn, Tumblr, and Pinterest followed with their own implementations.

Hashtags also found powerful applications in social justice. The #BlackLivesMatter hashtag, started by activists Alicia Garza, Patrisse Khan-Cullors, and Opal Tometi in 2013 following the acquittal of George Zimmerman, gained massive mainstream attention after George Floyd's death in 2020. The #MeToo movement, originally started by Tarana Burke in 2006, went viral as a hashtag in 2017 after revelations about Harvey Weinstein. Other notable hashtag campaigns include #JeSuisCharlie, the 2014 #IceBucketChallenge, and #BringBackOurGirls.

Beyond activism, communities worldwide used hashtags to challenge dominant media narratives. During Kenya's 2013 elections, Kenyans on Twitter created #TweetLikeAForeignJournalist to mock sensationalized international coverage, with tweets like "BREAKING: Masked men with sticks spotted fighting violently at a Fencing club". Similar campaigns like #UgandaIsNotSpain (after Spain's PM made a dismissive comparison) and #Ottawapiskat (turning Canadian government criticism language back on Ottawa) showed how hashtags gave historically underrepresented communities a way to reach global audiences through humor.

On January 4, 2013, the American Dialect Society voted "hashtag" as the 2012 Word of the Year, beating out "YOLO," "fiscal cliff," and "marriage equality" in a vote by more than 250 linguists, lexicographers, and historians. The term was added to the Oxford English Dictionary in June 2014 and Merriam-Webster that same spring. Scrabble also added "hashtag" to its Fifth Edition Official Scrabble Dictionary.

By the mid-2010s, hashtags had migrated beyond social media entirely. People used them in emails, text messages, and spoken conversation. The word "hashtag" itself became a punchline and cultural shorthand, with Urban Dictionary entries mocking overuse as "the international bat signal for white women" and late-night comedians riffing on the absurdity of saying "hashtag" out loud.

Fun Facts

Twitter co-founder Ev Williams initially dismissed Messina's hashtag proposal, saying it was too "geeky" for mainstream users

The # symbol's technical name is "octothorpe," coined at Bell Labs in the 1960s. The "octo" refers to its eight points, and "thorpe" may honor Olympic athlete Jim Thorpe, though the exact etymology is debated

Chris Messina graduated from Carnegie Mellon University with a communication design degree in 2003, four years before proposing the hashtag

The #AmazonFail hashtag in April 2009 was one of the first examples of collective Twitter outrage, and Clay Shirky's analysis of it became a widely cited essay on how social media can short-circuit critical thinking

In Singapore and Malaysia, the # symbol is commonly called "hex" and is used in apartment addresses to indicate floor numbers

Derivatives & Variations

Hashtag activism / #hashtag movements:

The use of hashtags to organize political and social campaigns (#BlackLivesMatter, #MeToo, #JeSuisCharlie, #IceBucketChallenge)[5]

Hashflags:

Twitter's custom implementation that replaces certain hashtags with small icons or national flags, first deployed during the 2010 World Cup[3]

Cashtags ($):

StockTwits adapted the hashtag concept in 2009 using $ instead of # to tag ticker symbols for stock market discussion[3]

Trending Topics:

Twitter's real-time display of popular hashtags, introduced in 2010 and later monetized through sponsored trends[18]

#GNO (Girls' Night Out):

A weekly Tuesday-night Twitter party started by mommy bloggers in 2008 that ran for years with hundreds of participants each week[11]

Hashtag memes for counter-narrative:

Communities using hashtags to challenge media coverage, including #TweetLikeAForeignJournalist, #UgandaIsNotSpain, and #Ottawapiskat[20]

Frequently Asked Questions

Hashtag

2007Social media convention / metadata tagclassic

Also known as: Hash tag · pound sign tag · # tag

Hashtag is a 2007 social media convention proposed by Chris Messina using # to prefix words or phrases for tagging and organizing posts around shared topics.

A hashtag is a word or phrase prefixed with the # symbol, used on social media to tag and organize posts around a shared topic. First proposed for Twitter by Chris Messina on August 23, 2007, the hashtag grew from a niche convention into one of the most recognizable features of online communication, eventually being named the 2012 Word of the Year by the American Dialect Society.

TL;DR

A hashtag is a word or phrase prefixed with the # symbol, used on social media to tag and organize posts around a shared topic.

Overview

A hashtag is a metadata label consisting of the # symbol followed by a word or phrase with no spaces. When someone includes a hashtag in a post, it groups that content with every other post using the same tag, making it easy to find and follow conversations about a specific subject. The format is dead simple: type #, add your keyword, and you've created a searchable link to a broader discussion.

Hashtags are not case-sensitive (#Hashtag and #hashtag return the same results), though CamelCase improves readability. The convention works across nearly every major social platform today, from X (formerly Twitter) and Instagram to Facebook, YouTube, TikTok, and LinkedIn.

The # symbol itself has ancient roots. It traces back to the Latin abbreviation *lb* for *libra pondo* ("pound in weight"), which scribes wrote with a horizontal line across to indicate abbreviation. Over centuries of hasty handwriting, that ligature morphed into the # we know today. The symbol appeared on typewriter keyboards in the 1870s and was added to Bell Labs' touch-tone telephone keypad in 1968.

The practice of using # to organize online discussions started on IRC (Internet Relay Chat) networks around 1988, where chat rooms were prefixed with the symbol followed by a topic name. But IRC hashtags were limited to people actually in the room.

Chris Messina, a Google user experience designer who earned his communication design degree from Carnegie Mellon in 2003, brought the concept to Twitter. On August 23, 2007, he tweeted: "how do you feel about using # (pound) for groups. As in #barcamp [msg]?". Two days later, he published a detailed blog post titled "Groups for Twitter; or A Proposal for Twitter Tag Channels," arguing that the # convention could let Twitter users follow topic-based conversations without needing to follow each other directly. He cited the March 2007 South by Southwest Interactive conference as an example of where hashtags would have been useful.

On August 28, 2007, web anthropologist Stowe Boyd responded with a blog post where he coined the actual term "hash tag" to describe the concept. Messina pitched the idea formally to Twitter co-founders Biz Stone and Ev Williams, but they reportedly told him hashtags were "for nerds" and would never catch on.

Origin & Background

Platform
IRC (original # convention), Twitter (modern hashtag proposal)
Key People
Chris Messina, Stowe Boyd
Date
2007
Year
2007

The # symbol itself has ancient roots. It traces back to the Latin abbreviation *lb* for *libra pondo* ("pound in weight"), which scribes wrote with a horizontal line across to indicate abbreviation. Over centuries of hasty handwriting, that ligature morphed into the # we know today. The symbol appeared on typewriter keyboards in the 1870s and was added to Bell Labs' touch-tone telephone keypad in 1968.

The practice of using # to organize online discussions started on IRC (Internet Relay Chat) networks around 1988, where chat rooms were prefixed with the symbol followed by a topic name. But IRC hashtags were limited to people actually in the room.

Chris Messina, a Google user experience designer who earned his communication design degree from Carnegie Mellon in 2003, brought the concept to Twitter. On August 23, 2007, he tweeted: "how do you feel about using # (pound) for groups. As in #barcamp [msg]?". Two days later, he published a detailed blog post titled "Groups for Twitter; or A Proposal for Twitter Tag Channels," arguing that the # convention could let Twitter users follow topic-based conversations without needing to follow each other directly. He cited the March 2007 South by Southwest Interactive conference as an example of where hashtags would have been useful.

On August 28, 2007, web anthropologist Stowe Boyd responded with a blog post where he coined the actual term "hash tag" to describe the concept. Messina pitched the idea formally to Twitter co-founders Biz Stone and Ev Williams, but they reportedly told him hashtags were "for nerds" and would never catch on.

How It Spread

Despite Twitter's initial indifference, early adopters ran with the idea. In October 2007, Nate Ritter used the hashtag #sandiegofire to post twelve hours of continuous news updates during the Southern California wildfires that burned nearly a million acres across the region. The tag drew attention from news outlets and blogs, proving hashtags could organize real-time information during breaking events.

Not everyone was on board. In a February 2008 blog post, content strategist Dave Coustan announced he would unfollow anyone who used hashtags, arguing they cluttered the conversational feel of Twitter with machine-readable metadata. "I want my Twitter to remain as human a form of communication as possible," he wrote. His stance captured the skepticism some users felt about the format's visual intrusiveness.

That same year, Twitter's mom-blogger community started using hashtags to host virtual parties. By November 2008, bloggers from Mommy Gossip (later Mom It Forward) launched a weekly Tuesday-night "Girls' Night Out" under the hashtag #gno, attracting 250-500 participants sending over 1,500 tweets per hour. Sitewarming parties organized by mommy blogger Amy Bair regularly pushed their hashtags to the top of Twitter Search trending topics within minutes.

In early 2009, how-to guides for using hashtags started appearing on tech blogs like Mashable. Then in April 2009, the format got its first major stress test when Amazon appeared to de-rank LGBT-themed books from search results. The hashtag #AmazonFail spread rapidly across Twitter as users organized collective outrage. NPR covered the backlash, the Wall Street Journal coined it a new term, and internet researcher Clay Shirky published a now-famous analysis calling the hashtag's viral spread both a "failure" and an "intoxicating" experience, noting how the emotional rush of joining a righteous hashtag campaign could override critical thinking.

How to Use This Meme

Hashtags follow a simple format:

1

Type the # symbol followed immediately by your word or phrase (no space between # and the word)

2

No spaces or special characters within the hashtag. Multiple words run together: #ThrowbackThursday, not #Throwback Thursday

3

Keep it concise. #bizducks works better than #businessofthecallingducksconference

4

Give context. If creating a new hashtag, explain what it's for in your first few posts

Cultural Impact

Hashtags fundamentally changed how information spreads online. They gave ordinary users the power to create and join conversations at scale, without needing permission from any platform or gatekeeper.

In marketing, brands built entire campaigns around hashtags. Calvin Klein's #MyCalvins encouraged users to post photos in their underwear. Red Bull's #PutACanOnIt promoted creative photos with their product. Expedia's #ThrowMeBack campaign offered travel vouchers for nostalgic posts. But brand hashtag campaigns also backfired spectacularly at times, as companies discovered they couldn't control how the public would use an open tag.

In politics and social justice, hashtags became organizational tools for real movements. The Arab Spring protests, Occupy Wall Street, Black Lives Matter, and Me Too all used hashtags as rallying points that could spread faster than any traditional organizing method.

Messina, the inventor, never attempted to patent the concept. "They were born of the internet, and owned by no one," he said. He continued working in tech and is recognized by Carnegie Mellon University as a notable alumnus.

Full History

Twitter finally built official support for hashtags on July 2, 2009, hyperlinking all hashtagged words in tweets to search results. This was nearly two years after Messina's original proposal, but it changed everything. In 2010, Twitter introduced "Trending Topics" on its homepage, displaying the most popular hashtags in real-time. The company started selling sponsored trending topics to brands like Disney, Coca-Cola, and Hyatt for a reported $100,000-$120,000 per day. During the 2010 World Cup, Twitter deployed "hashflags" that replaced three-letter country code hashtags with national flags.

The 2009-2010 Iranian election protests marked a turning point for hashtags as tools of political activism. Twitter users employed both English and Persian-language hashtags to coordinate and share information during the events. This set the template for a decade of hashtag activism that would follow.

Other platforms took notice. YouTube began supporting hashtags, and real-time search services like Google Real-Time Search incorporated them. Instagram, which launched in 2010, made hashtags central to content discovery. Posts with at least one Instagram hashtag averaged 12.6% more engagement than those without. Facebook added hashtag support on June 12, 2013, though its implementation was limited by privacy settings. Users could only see public posts and content shared by friends, unlike Twitter's fully open search model. LinkedIn, Tumblr, and Pinterest followed with their own implementations.

Hashtags also found powerful applications in social justice. The #BlackLivesMatter hashtag, started by activists Alicia Garza, Patrisse Khan-Cullors, and Opal Tometi in 2013 following the acquittal of George Zimmerman, gained massive mainstream attention after George Floyd's death in 2020. The #MeToo movement, originally started by Tarana Burke in 2006, went viral as a hashtag in 2017 after revelations about Harvey Weinstein. Other notable hashtag campaigns include #JeSuisCharlie, the 2014 #IceBucketChallenge, and #BringBackOurGirls.

Beyond activism, communities worldwide used hashtags to challenge dominant media narratives. During Kenya's 2013 elections, Kenyans on Twitter created #TweetLikeAForeignJournalist to mock sensationalized international coverage, with tweets like "BREAKING: Masked men with sticks spotted fighting violently at a Fencing club". Similar campaigns like #UgandaIsNotSpain (after Spain's PM made a dismissive comparison) and #Ottawapiskat (turning Canadian government criticism language back on Ottawa) showed how hashtags gave historically underrepresented communities a way to reach global audiences through humor.

On January 4, 2013, the American Dialect Society voted "hashtag" as the 2012 Word of the Year, beating out "YOLO," "fiscal cliff," and "marriage equality" in a vote by more than 250 linguists, lexicographers, and historians. The term was added to the Oxford English Dictionary in June 2014 and Merriam-Webster that same spring. Scrabble also added "hashtag" to its Fifth Edition Official Scrabble Dictionary.

By the mid-2010s, hashtags had migrated beyond social media entirely. People used them in emails, text messages, and spoken conversation. The word "hashtag" itself became a punchline and cultural shorthand, with Urban Dictionary entries mocking overuse as "the international bat signal for white women" and late-night comedians riffing on the absurdity of saying "hashtag" out loud.

Fun Facts

Twitter co-founder Ev Williams initially dismissed Messina's hashtag proposal, saying it was too "geeky" for mainstream users

The # symbol's technical name is "octothorpe," coined at Bell Labs in the 1960s. The "octo" refers to its eight points, and "thorpe" may honor Olympic athlete Jim Thorpe, though the exact etymology is debated

Chris Messina graduated from Carnegie Mellon University with a communication design degree in 2003, four years before proposing the hashtag

The #AmazonFail hashtag in April 2009 was one of the first examples of collective Twitter outrage, and Clay Shirky's analysis of it became a widely cited essay on how social media can short-circuit critical thinking

In Singapore and Malaysia, the # symbol is commonly called "hex" and is used in apartment addresses to indicate floor numbers

Derivatives & Variations

Hashtag activism / #hashtag movements:

The use of hashtags to organize political and social campaigns (#BlackLivesMatter, #MeToo, #JeSuisCharlie, #IceBucketChallenge)[5]

Hashflags:

Twitter's custom implementation that replaces certain hashtags with small icons or national flags, first deployed during the 2010 World Cup[3]

Cashtags ($):

StockTwits adapted the hashtag concept in 2009 using $ instead of # to tag ticker symbols for stock market discussion[3]

Trending Topics:

Twitter's real-time display of popular hashtags, introduced in 2010 and later monetized through sponsored trends[18]

#GNO (Girls' Night Out):

A weekly Tuesday-night Twitter party started by mommy bloggers in 2008 that ran for years with hundreds of participants each week[11]

Hashtag memes for counter-narrative:

Communities using hashtags to challenge media coverage, including #TweetLikeAForeignJournalist, #UgandaIsNotSpain, and #Ottawapiskat[20]

Frequently Asked Questions