A Scientific Guide to Hashtags: How Many, Which Ones, and Where to Use Them

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hashtagHave you ever found yourself explaining hashtags to someone whose only connection with the word is as a telephone button?

Internet language has evolved considerably over the past few years as social media has taken off. Hashtags are a huge part of this evolution. What once was a telephone button is now a social media phenomenon.  No wonder people are curious.

When they ask, I tell them that hashtags are a pound sign immediately followed by a keyword. They’re used for categorization on social media. Yes, they can be annoying if overused. And yes, I’ve seen the hashtag video of Jimmy Fallon and Justin Timberlake.

Hashtags also have the potential to be truly valuable. The stats and info below make a pretty clear case that we should be understanding, using, and appreciating hashtags.

Research says you should be using hashtags

If you’re looking for a completely cut-and-dry ruling on the topic of hashtags, then here it is: You should be using hashtags.

The proliferation of hashtags is truly incredible. What began on Twitter has now spread to Facebook, Google+, Instagram, Google search, and almost everywhere in between. (LinkedIn experimented with hashtags for awhile before giving up.)

The widespread acceptance of hashtags should give you plenty of reason to consider using them. I also really enjoy the case laid out by Steve Cooper, writing for Forbes.com:

As ridiculous as hashtags might seem to marketing veterans who remember a time before Twitter and Facebook, the younger generation and potential customers/clients don’t. To them, using hashtags is as natural and common as typing their query into the search box.

Not only could people be typing in your hashtag on a Google search, but they could very well be doing it in Twitter, too. In this sense, a hashtag will make your content viewable by anyone with an interest in your hashtag, regardless of whether they’re part of your clan or not.

A hashtag immediately expands the reach of your tweet beyond just those who follow you, to reach anyone interested in that hashtag phrase or keyword.

But how do you find the right hashtags for your content and make sure you’ve got them in the right number, on the right social network? Let’s break it down.

Hashtags on Twitter

Tweets with hashtags get two times more engagement than tweets without.

This data, courtesy of Buddy Media, is one of the most-cited examples of the effectiveness of hashtags, and for good reason: doubling your online engagement is a big deal! Imagine going from four retweets to eight or 10 retweets to 20. And all it takes is a simple # or two?

Apparently so. Although, you’ll want to keep it to no more than two.

Buddy Media’s research also showed that the volume of hashtags bears monitoring: one or two hashtags appear to be the max. When you use more than two hashtags, your engagement actually drops by an average of 17 percent.

Twitter hashtag stats

Twitter’s own research into hashtags confirms that there is significant advantage to using them. Individuals can see a 100 percent increase in engagement by using hashtags (the same bump as seen in the Buddy Media study). Brands can see a 50 percent increase.

Engagement, as measured in these studies, can include clicks, retweets, favorites, and replies, yet if it’s only retweets your after, hashtags still would be a smart bet.

Tweets with one or more hashtag are 55 percent more likely to be retweeted.

Dan Zarella discovered this effect in a study on retweeting behavior that included more than 1.2 million tweets. The large scope of the study made for a 99.9 percent confidence interval with the results.

Hashtags and retweets

Hashtags on Instagram

Instagram is another hotspot for hashtags, and the good news for those who love to extensively tag photos is that there doesn’t seem to be a saturation point.

Interactions are highest on Instagram posts with 11+ hashtags.

A rule of thumb could be: Don’t sweat your amount of Instagram hashtags.

instagram tips, instagram statistics, instagram stats

The best part about this recommendation is that the data comes from a set of users with 1,000 or fewer followers—a group that likely includes small businesses and those just diving in to Instagram. In other words, hashtags could be your best bet for growing a fast following on Instagram.

Hashtags on Facebook

So yes, Twitter and Instagram are clear winners for hashtags. But what about Facebook? Here’s where the recommendation gets a little trickier.

Facebook posts without a hashtag fare better than those with a hashtag.

Hashtags have only been around on Facebook since June 2013, and three months later, research from EdgeRank Checker found that using hashtags on Facebook has zero positive effect on reach. Posts without hashtags outperform those with hashtags.

Facebook hashtag study


A lot could have changed since September, when this data was first released. Should you abandon hashtags on Facebook solely due to this research? It’s probably best to test. There’s still a lot of analysis left to be done. For instance, Social Bakers studied posts in February of this year and found that using hashtags might not be the main worry, but rather using too many hashtags (just like the advice on Twitter).

Too many hashtags

Hashtags on Google+

On Google+, your posts are given hashtags automatically based on their content, but you can also edit them or add your own. Also unique about Google+: You can add hashtags in your comments as well as your post – double the opportunities to be found.

And since Google+ is Google’s social network, hashtags are now built right into Google searches. If you type in a hashtag search, you’ll get the normal search results plus a sidebar of relevant Google+ posts. Hashtags have truly arrived!

Hashtag search Google

Google+’s “related hashtags” also offer smart marketers a brainstorming opportunity to discover new content ideas and gauge interest level in specific topics.

Tools to find and manage your hashtags

Using the right tools, you can use hashtags as an organization system for your social media campaigns. With everything collected under one hashtag banner, you can see at-a-glance the reach of your campaign and the discussions happening around the topic.

One of the most complete hashtag tools you will find, Hashtagify.me has reams of data you can use to analyze hashtags. The most helpful could very well be the first data you’re shown: related hashtags and their popularity. When you type in a hashtag, the service will show you other hashtags to consider and will display visually how popular each hashtag is and how closely it correlates to the original.


RiteTag helps ensure that the tags you use are well-chosen by showing you how good, great, or overused a particular hashtag is. The visual organization of hashtags into colored bars works great for quick analysis at-a-glance.


With Tagboard, you can see how your hashtag is used across multiple networks. The results pages on Tagboard show hashtagged posts from Twitter, Facebook, Instagram, Google+, Vine, and App.net


Though not an explicitly hashtag tool, Twitalyzer does show hashtags as part of its audit of Twitter accounts. Input the username of someone you want to investigate, and Twitalyzer can tell you what hashtags he or she uses most often. This can be really helpful in finding out how your niche’s influencers tweet.


Local businesses might find value in Trendsmap, which shows you relevant hashtags that are being used in your geographic area. (#wrestlemania is a popular one where I am in Idaho.)

4 steps to find the right hashtag to use

Using the tools above, you can hone in on a few ideal hashtags to start with, and like most things online, test and iterate from there.

1. Learn from the best: What hashtags are influencers using?

Twitalyzer can give you a good foundation of where to begin for your hashtag search by showing you how influencers are using hashtags. Grab a handful of usernames of people and brands in your industry whom you admire, and input the accounts into Twitalyzer. At the bottom of the results page, you’ll see a section for their most commonly-used hashtags. Add the relevant ones to your list of potential hashtags.

Let’s say I wanted to find some hashtags to use in promoting social media marketing content. I might start with a list of names like Jeff Bullas, Jay Baer, Mari Smith, and Ann Handley. Here is what the hashtag results on Twitalyzer look like for Jeff Bullas:

 Twitalyzer results


Info like this would lead me to start a short list of hashtags like:

  • #socialmedia
  • #SMM
  • #twitter
  • #contentmarketing
  • #social
  • #content
  • #marketing

2. Cover all your bases: Are there related hashtags you should be considering?

Armed with an idea list of hashtags, you can then hop into Hashtagify.me to see which related hashtags might also be worth pursuing. While you’re doing this exercise, take note of the circle size on your results: The larger the circle, the more popular the hashtag.

Again, following our social media marketing example, here is what the results page would look like for a search of #socialmedia:

Hashtagify.me results

Not every hashtag listed here will be relevant to you, but it does help to see some that you might not have previously considered. In the case of our example, I might add #business, #infographic, and hashtags of specific network names like #twitter and #facebook.

3. Identify the all-stars: Which hashtags are the best to use?

Popularity and volume can be good indicators of the value of your hashtag, but you may wish to go one step further. Hashtagify.me has advanced, premium tools that let you go deeper into statistics on individual hashtags. In a pinch, you can also get some solid data from RiteTag and their visual expression of how much each tag can boost your post’s reach. 

Among posts that contain the word “marketing,” RiteTag shows these tags as the most likely to be great, good, or overused. (There’s that #wrestlemania tag again!)



RiteTag results

4. Double check: Could your chosen hashtags mean something else entirely?

One last check before you finalize your list of hashtags should be whether or not the hashtag you’ve chosen is being used elsewhere in an entirely different context.

The worst thing that can happen when using a hashtag is to realize after it’s tweeted that the same hashtag is used for an entirely different topic.

Jawbone tried a #knowyourself campaign on Instagram, only to find that the hashtag was already being used generically by thousands of users in all sorts of different contexts. This didn’t necessarily ruin Jawbone’s campaign, but it may have made life a little more difficult for the marketing team. 


Hopefully you’ve learned the value of hashtags here and a few neat ideas on how to find some to use in your social sharing. If you’re looking for a simple rule of thumb for hashtagging posts, I think there’s a lot of truth here in this advice from The Next Web:

Rule of thumb: 1 – 3 tags is best over all platforms.

  • Twitter: to categorize

  • Pinterest: to brand, and be specific (tags are only clickable in pin descriptions)

  • Instagram: to build community, and be unique/detailed

  • Google+: to categorize; autogenerates tags based on what it thinks your post is most relevant to

  • Tumblr: to categorize interests, can be specific and general (has a “track your tags” feature)

  • Facebook: sort of a hashtag fail – if your audience is very business-minded, follow Twitter rules; if it is community-oriented, follow Pinterest/Instagram rules

What hashtags do you routinely use on social media? I’d love to hear how you’ve put hashtags to work in your social media strategy.

P.S. If you liked this post, you might enjoy our Buffer Blog newsletter. Receive each new post delivered right to your inbox, plus our can’t-miss weekly email of the Internet’s best reads. Sign up here.

Image credit:mikecogh

  • http://tunahack.com Rob McNelis

    Timely post. Neil Patel just did one on hashtags. Seems like everyone is running out of stuff to write about. lol

    • http://blog.bufferapp.com Kevan

      We’ve got hashtags on the brain! I’ll have to coordinate with Neil next time. :)

      • http://tunahack.com Rob McNelis

        Haha I think its all apart of some big master plan for world domination. Buffer and Quick Sprout are ninjas. :)

  • Ashok Kamal

    Twitalyzer shut down last year but thanks for the tip on Hashtagify.me.

    • http://blog.bufferapp.com Kevan

      Thanks for this info, Ashok! Hadn’t heard the news about Twitalyzer. That’s too bad. Maybe their infrastructure was left behind? The site worked for me the other day when I was testing it. :)

      • Ashok Kamal

        No prob. I think they’re sun-setting the service …

        • http://blog.bufferapp.com Kevan

          Got it. Catch it while you can! :)

  • Mike Madura

    Any thoughts or research regarding the number of hashtags in Twitter bios vs. Tweets?

    • http://blog.bufferapp.com Kevan

      Great question, Mike! Bio research eluded me for this article, but I’m happy to share thoughts. I’d imagine that you’d see less effect from hashtags in bios since searchable content is where much of the hashtag value lies. How does that sound to you?

  • http://www.3hatscommunications.com/blog/ Davina K. Brewer

    Love the breakdown by social network; not all communities are the same, so it makes sense that some hashtags will change from network to network. And via the various tracking/measurement tools, you can track effectiveness maybe do some A/B testing of different hashtags, to see what works best for a particular campaign or story. Doing your homework can also help you stand out more, drill down from a broad widely used hashtag to a related, less used one that’s more targeted. FWIW.

  • Chase Fleming

    Good post. http://www.hashtagscout.com/ is another tool.

  • http://www.amazon.com/author/stevevera Steve Vera

    Great breakdown of hashtags, thank you! Little by little I’ll get this social media thing down…

  • Guest

    @kevanlee:disqus Many thanks for including one of the hottest features of RiteTag in this darn good article. I’m the product guy/founder, and I thought I’d tip you and readers off to what I demonstrate in the attached GIF. Once a user is set up and goes for a paid plan, they get the hashtag grading within Buffer. Yup!
    The thing is, they could also be getting that (and another RiteTag goodie) as Buffer added-value features, and without using RiteTag – if Buffer uses our API (going live this month).

  • http://osakabentures.com/english-2/saulfleischman/ Saul Fleischman

    Kevan Many thanks for including one of the hottest features of RiteTag in this darn good article. I’m the product guy/founder, and I thought I’d tip you and readers off to what I demonstrate in the attached GIF shown at https://plus.google.com/100575455878135404735/posts/bUYkwcuWxSs (sorry – only way I found to get an animated gif to show here).

    The thing is, they could also be getting that (and one other really sweet RiteTag goodie) as Buffer added-value features, and without using RiteTag – if Buffer uses our API (going live this month). For the coming attraction, see items 1 and 2 in http://ritetag.com/rest-api – the RiteScore and Associated Hashtags.

    Pass this up the totem pole, if you would…?

    • http://blog.bufferapp.com Kevan

      Really interesting integration here, Saul! I’ll be happy to pass it up the totem pole. :)

    • Ruth

      I would really like this! Often wish I could see hashtag recs/judgements from Buffer while I’m posting from a website.

      • http://osakabentures.com/english-2/saulfleischman/ Saul Fleischman

        Good to know, Ruth. “Judgements” – I like that. I’ve been calling it “grading.” And it happens within a few seconds of you typing a hashtag in the Buffer post. If you check out the animated gif above, you’ll see that first I hashtagged #hashtags, got a “good” grade for that, but improved to a “great” by changing to #hashtag.
        Also, we can provide an associated hashtags pull-down, but that’ll depend on whether the Buffer people want that or not.

  • Michelle C

    Thanks for another informative post. I have been wondering if it does much good to use hashtags on pinterest- any idea where to get more info on that?

  • Suzi Hixon

    Thank you Kevan! I was looking through the comments and Ashok mentioned below that Twitalyzer had shut down. That’s super disappointing because that would have been a great resource. Any suggestions are related alternatives? Again, thanks!!!

    • Suzi Hixon

      http://www.twitalyzer.com appears to be active

      • http://downandoutindk.blogspot.com/ Hallies Comet

        It’s up, but they’re not taking any new subscribers, so if you don’t have an account, you can’t get one

        • http://boutiquejapan.com/ Andres Zuleta

          Twitalyzer is “shut down” for new subscribers. Bummer!

          Great article though, but the whole Twitalyzer portion is not usable for those of us who did not have accounts.

          Anyway, Kevan your work is always good, keep it up!

  • Jessica Rudder

    I’ve definitely seen a boost for tweets with hashtags from my startup @NativLang.

    I wonder if hashtags only provide a boost to engagement by expanding the reach of your posts (which is not hard to do when you have a modest 32 followers like us). :)

    If the hashtag didn’t reach outside of your followers or it were a silly hashtag unlikely to have a huge following (#LikeThisOneForExample), would the boost still be there? Perhaps as a result of signaling that you part of the Twitter in-crowd?

    • http://osakabentures.com/english-2/saulfleischman/ Saul Fleischman

      @jessicarudder:disqus Whenever I pitch RiteTag I use cases like your’s as an example of our value proposition. Although for brand new accounts it takes weeks before you show up in hashtag search/clicked results, after that happens, you have 32 followers / I have 25,700. And the way you beat me is with the right hashtag.
      To your other points: we’ve found no evidence that silly gets you much, but really long hashtags are nearly always a mistake. Finally, more that signalling an in-crowd thing, using 1-3 relevant and reaching hashtags is read by some people as you putting care in your tweets (and that you take Twitter seriously).

      • http://blog.bufferapp.com Kevan

        Great conversation here, Jessica and Saul. It’s like a mini blog post of its own. :)

        Thanks for the added info. I love the point about hashtags showing people you put care into your tweets. Great perspective.

  • http://www.blog.mobiloitte.com Blaze Arizanov

    My measurement for a quality of a blog post is the quantity of takeaways.

    I did not know about Twytalizer… Hence, good going

  • Mike

    Awesome post like always. Thanks Kevan, for yet again helping us benefit with such a detailed write up!

  • http://about.me/astivelman Andrew Stivelman

    I really like this article. I find it difficult sometimes to find the URL in a tweet among all the hashtags that people include, and the more it gets retweeted the more hashtags that appears (sometimes). I like your statement: “When you use more than two hashtags, your engagement actually drops by an average of 17 percent.”

  • Luca Forest

    Nice post …helped me a lot. Thanks :)

  • Hananya

    I use the same hashtags all the time on my Instagram and it works just fine instagram.com/hnaftali

  • Olsoweir

    This is such a good article!

  • http://www.webwisedom.com/ Mike Wise

    Great article and discussion. Absolutely spot on. Thanks for sharing and promoting.

    The one thing I’d add is that the more popular a hashtag is, the faster your content will be pushed out of view by newer mentions. This effect will only accelerate as more people begin to use them more often. The paradox of doing something ‘popular’on Social. Yes, you’re in with the crowd. But you’re in with the crowd!

    I’d also point to the utility of hashtags around events extremely effective, especially with hashtag recap tools like storify and tweetbinder.

    Thanks again.

    • http://blog.bufferapp.com Kevan

      Love the way you put this, Mike! There’s definitely a paradox with being in the “in crowd.” One of the nice features about RiteTag is that it’ll tell you if your hashtag is overused or not, hopefully sparing you from getting too deep with the in-crowd. :)

  • Anita

    Great article! Thanks for sharing.

  • Ola Agbaimoni

    Hi Kevan great article. Really useful information about the tools to make using #hashtags more effective. Why did you say #hashstag is a £ sign followed by a keyword? it’s a # sign which I thought was the symbol for number – have I missed something?. Most annoying thing about t#hashtags is they are in different places on different keyboards (and sometime invisible to the naked eye lol).

    From my experience of them, they are useful for monitoring if you make your own ones up but you don’t get as much traction as you do if you use the more popular ones, then you end up with the paradox that Mike referred to.

    thanks for sharing this Big Hugs :~D

  • Branko Kral

    awesome awesome awesome!

  • Jennifer Adams

    Excellent article. Wish everyone would read this! Hate seeing so many hashtags in one post. Big pet peeve of mine….hashtags on Facebook. Thanks for the information!

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  • http://www.capturelife.com Scott DeFusco

    I was just exploring how to analyze trending hashtags this morning and presto! This post landed in my feed. Are you watching us? Great tips. Thanks!

  • Steve

    Interesting how too many hash tags switch people off.

    As a newbie using twitter to promote my science education website
    newtonsapple.org.uk I found I have increased traffic through using fewer, rather than more hashtags.

    People don’t bother reading tweets if they are overloaded with hashtags (I certainly don’t!)

  • Lyndon

    “Twitter’s own research in to Hashtags shows…” should be all the evidence you need to know that the end of the sentence will suggest there is a benefit to using them! Hardly science.

    Also, define engagement. What does it actually mean in social? Somebody shares something? You can join a conversation with like-minded users? That’s great – but where is the long-term relationship or marketing value?

    • Courtney Seiter

      Hey Lyndon! As we’re using it here, engagement includes clicks, retweets, favorites, and replies. I’d say the long-term value is reaching the right audience and creating brand awareness, trust, credibility and usefulness with your content and social media presence. :)

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    TAGCANDY claim is that they will provide 100 percent guarantee for his or her service and facilitate anyone in achieving the target.

  • http://www.hshdsh.com Pallab Kakoti

    Incredible incredible post // many thanks for sharing this // kudos to you // cheers! #plbkkt via #hshdsh

  • sopularity

    Great post Kevan! If you are searching for the most appropriate hashtags for your tweet, you may use the sopularity tool. It suggests the best hashtags for a given tweet, see http://www.sopularity.com

  • Faux Wood Beams.com

    What about hashtags on Pinterest? I hear both pros and cons but haven’t seen any real evidence on whether to use or avoid them.

    And thanks for the article, Kevan! It’s another winner. :-)

    • http://blog.bufferapp.com Kevan

      Great question! I’ll keep my eyes open for research on this, and I’ll be happy to report back. Might warrant a followup to this post!