The Twitter Hashtag: What Is It and How Do You Use It?

Last Updated: April 24, 2015

Hashtag: I Don't Get ItOnce you’ve started using Twitter, it won’t take long before you come across what’s known as a hashtag. That’s when you see something in a tweet that has a # prefix. (The # is a hash symbol, hence the term hash tag or, more commonly now, hashtag.)

For example, if you’ve seen tweets related to the recent typhoon that has devastated the Philippines, you may have noticed some of them had #Haiyan in them.

When I first saw them, it took me a while to wrap my head around what the purpose of this thing was. But, once I “got it,” I realized it’s not as complicated as it seems.

A hashtag is simply a way for people to search for tweets that have a common topic. For example, if you type #Gravity (or #gravity or #GraVItY, because it’s not case-sensitive) into the Search Twitter box at the top of any Twitter page and hit Enter, you’ll get a list of tweets related to the movie. What you won’t get are tweets that say “Who discovered gravity?” because “gravity” isn’t preceded by the hashtag.

Note: Your search results will give you three options for filtering the list. The default is Top. I’m not sure how they decide what counts as top, although I imagine it has to do with the number of followers a tweeter has or the number of times the tweet has been retweeted. You can also show a list of All tweets with that search term or only those from people you follow.

The good thing about the hashtag is that if someone wrote a tweet without putting the word Gravity in the main message, it will still show up in your search because of the tag. Eg. “Just saw this year’s best picture. #Gravity”

The flip side is that if you search using the tag, and someone wrote a tweet about the movie without including it, that tweet may not show up in your results, even if Gravity appears in the text. Eg. “Who thinks Gravity will win Best Picture this year?” (Sometimes it does, but not always.)

In a way, hashtags allow you to create communities of people interested in the same topic by making it easier for them to find and share info related to it.

Where do hashtags come from?

I think this question gets to the heart of the confusion about these danged things, because hashtags are NOT any kind of official Twitter function. The company has not created a list of topics that we can browse through to see if there’s one that interests us.

So where DO they come from? Well, any user can create one simply by adding it to their own tweet. For example, when a plane went down in the Hudson River a few years ago ago, some Twitter user wrote a post and added #flight1549 to it. I have no idea who this person was, but somebody else would have read it and when he posted something about the incident, added #flight1549 to HIS tweet. For something like this, where tweets would have been flying fast and furiously, it wouldn’t have taken long for this hashtag to go viral and suddenly thousands of people posting about it would have added it to their tweets as well. Then, if you wanted info on the situation, you could do a search on #flight1549 and see everything that people had written about it.

When hashtags first started being used, it was a very organic process that worked simply because of a group mindset that people like to categorize topics and this was one way to make it easier to do so.

Now that they are so common, they really only show up spontaneously if there’s a breaking news item. Otherwise, they’re used to promote, praise, or pan people (#Malala), brands (#Lego), events (#StanleyCup), and anything else people want to discuss en masse (#bacon).

There are a few other common ways hashtags are used as well:

  • Group Activities. These are things like college classes, conferences, clubs, associations, or online events, where there’s a certain group of people who want to share information among themselves through tweets (although be aware they’re still available to the general public). For example, a writer friend of mine, Michelle Rafter, runs a blog called WordCount with information for other writers. On the last Wednesday of each month, she hosts a Twitter chat around a theme and everyone who participates adds the hashtag #wclw (for WordCount Last Wednesday) to each tweet so everyone can follow along.
  • Update 11/15/13: My new favorite hashtag is one that was created for probably THE best group activity EVER: #SFBatKid.

  • Online Conventions. These are usually short terms or abbreviations that have become common ways to express certain concepts. Some examples are #shoutout, #nowplaying, #tbt (Throwback Thursday).
  • Asides. These are little extras people add to their tweets to express the way they feel or make a comment about what they just tweeted, e.g. #blessed, #mustread, #smh (shaking my head).

Note: Even though I’ve been talking about hashtags as they apply to Twitter, they are also now commonly used by other social media sites, including Instagram, Pinterest, Tumblr, and Facebook.

How do I track topics of interest to me?

The first thing you would do is a basic Twitter search to see if a related term already exists. These days, odds are it does. In fact, I’ve been trying to think of something so obscure that one doesn’t exist (#underwaterbasketweaving, anyone?) and haven’t had success yet!

Probably the only reason you would need to create a new one nowadays would be for the group activities category I mentioned above. In that case, since the tag will use up some of your 140-character limit, you want to keep it fairly short, while still making it precise so other people aren’t likely to use it for another purpose. For example, let’s say I wanted to create a virtual book club with my friends scattered around the country. I might create the #ekbookclub hashtag that we would all add to the tweets we’re posting about the books we’re reading.

If you want more than just your friends to use the hashtag, you might want to “announce” it to your followers. For example, I created a hashtag called #tech4ludds for any tweets that people want to associate with Tech for Luddites. I did it by posting this:

Starting a new hashtag for Tech for Luddites. Got a question for me or a great tech tip to share? Add this to your tweet. #tech4ludds

This way, I’m letting my followers know that this now exists, so they can add the hash tag to their own tweets if they think it’s related to this blog somehow.

I originally wanted to create a tag for t4l for brevity but there was already a single tweet in existence at that time using that tag, if you can believe it! It was in Dutch and had a link to the Netherlands Unicef site. A Google search led me to believe it stood for Time for Learning. Probably a great program but still… Bummer. (That tweet is long gone but the hashtag is now used for all sorts of other tweets, so I gave up on it.)

This is probably the most common question I get about hashtags. There are two possible issues here. One has to do with whether there’s an issue with the hashtag itself. Twitter’s Help page explains some of the problems you can run into—for example if a hashtag is made up entirely of numbers, Twitter doesn’t make it searchable. However, in most cases, this is NOT the problem.

Instead, the problem is actually with Twitter’s own search feature. This Help article explains some of the factors that may be affecting you as well. For example, maybe you’ve got your page set to Top Results instead of All or maybe your tweets are protected. But the most important sentence on this page is buried near the bottom in the blue box:

Keep in mind that not all Tweets are indexed.

This article doesn’t say so, but Twitter used to publicize that they only index the last two weeks’ worth of tweets in total. But even if your tweets fall in that time frame, yours may not show up. You can try to contact Twitter Support to see if they can help you, especially if you’re using a hashtag to help people follow along during an event or for a specific use like a class ID, but no guarantees…

I hope the above helps explain how hashtags work and why you might want to use them. If you have any other questions, please post them in the comments below or send an email to


Related Stories

Using hashtags on Twitter (Twitter Help)

#HashTagsGoneWild (T4L)

Join Me Today in a Twitter Chat on Monetizing Your Blog (T4L)

#ILovesMeSomeJimmyAndJustin (T4L)

The Hashtag Is About to Roll Out to a Billion People, and This One Guy Invented It (The Atlantic)

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  1. Joni says

    Thank you for the info
    I get tired of asking my kids questions
    Or better yet my kids are so tired of explaining to me
    My son always says “mom I’m not going to leave till you do it on your own, you can’t keep calling me to (set up whatever) ” fill in the blank. So I’m gonna give it a try…#keepingup #techchallenged
    So tell me how I did. ???

  2. Carol says

    I started reading this and about half way through my head started hurting soooo bad! To me the hashtags (aka pound sign for years!) are just a pain and un-needed!

  3. says

    Hi there. Love and appreciate the info! Wonder if you could help me. My twitter account is 60secondparis, like my website…and which posts to it, my site and twitter account is aimed at offering non touristy real hidden and unique glimpses of Parisian life. To make it better I looked up “hiddenparis” and found a twitter account with a huge following but also it listed ‘similar accounts’ to that one. And mine wasn’t there!! How do get my account to show up as one of those under ‘hidden paris’ or something like Unique or Secret paris …which is what it is about???? Do I need to better define the bio on my twitter account? Are there some tools I’m not, but should be using. It’s very frustrating not to appear in a category you think you should be in. Any insights, help appreciated!

    • Elizabeth Kricfalusi says

      Hi David.

      Were you searching for “hiddenparis” on Twitter itself? What was the site that came up?

      It’s possible that Twitter didn’t show you your account because you were doing the search so it knows you already know you. :) But I’d like to see if your site shows up for me in the same situation.

      – Elizabeth