What are LSI keywords? Everyone seems to be talking about them...
...and for good reason.
It's the way search engines decide which pages are relevant to a given search query.
In this article I'm going to show you everything you need to know about LSI keywords and how to take advantage of them:
- 1. What Are LSI Keywords?
- 2. Why Does Google Use LSI Keywords?
- 3. Hummingbird and LSI Keywords
- 4. How Can LSI Keywords Improve Your Ranking?
- 5. Where To Find LSI Keywords?
- 6. How To Use LSI Keywords?
- 7. What To Avoid With LSI Keywords
- 8. Conclusion
1. What Are LSI Keywords?
LSI keywords (Latent Semantic Indexing) are keywords semantically related to your main keyword. A lot of people think that LSI keywords are synonyms. But this is not entirely true.
While some LSI words may be synonyms, most LSI keywords are simply words that are frequently found together because they share the same context.
For example, 'apple' and 'itunes' are LSI keywords because they share the same context and are frequently found together. But they are not synonyms.
Here are some examples of how LSI works.
Let’s say your page or blog post is about Cars (thanks to Nikolay for this example).
You could be writing about any of the following 5 meanings of ‘Cars’:
- Cars the vehicle
- Cars the animated Disney movie
- CARS, the Canadian Association for Rally Sports
- CARs, the Canadian Aviation Regulations
- (The) Cars, the American 1970s music band
How does Google know which meaning of ‘Cars’ is relevant for your page?
Google will be looking for LSI keywords on your page to decide which is the correct meaning:
- If it finds the words: 'vehicle', 'used', 'new', 'buy', 'sell', 'dealers', 'repair', your page is probably about cars, the vehicle
- If it finds the words: 'film', 'movie', 'produced by', 'directed and co-written by', 'motion picture', 'Walt Disney', your page is most likely about Cars, the movie
- If it finds the words: 'association', 'rally', 'sport', 'championship', 'Canadian', your page is probably about CARS, the Canadian Association for Rally Sports
- If it finds the words: 'aviation', 'regulations', 'administration', 'aerial', 'aerodromes', 'airports', your page is most likely about CARS, the Canadian Aviation Regulations
Here’s another example (thanks to Fedingo Marketing for this one):
Let’s say your page or blog post is about Apple.
How does Google know if you’re referring to the fruit or the company?
It looks for LSI keywords:
- If your page contains the words: 'baked apples', 'red apple', 'green apple', 'apple nutrition', 'fuji apples', 'honeycrisp apple', 'eating apple', your page is probably about apples, the fruit
- If your page contains the words: 'itunes', 'apple hulu', 'apple news', 'apple stores', 'apple iphone 5', 'apple new ipad', 'apple stock price', 'discount computers', your page is most likely about apple computers
So why did Google start using LSI keywords?
2. Why Does Google Use LSI Keywords?
There was a time when the only measure Google had for relevancy of a page to a given search query was keyword density.
As we all know, keyword density was horribly abused and spammed.
So Google moved away from keyword density and began looking at LSI keywords.
The reasoning was this:
A legitimate page about ‘Apple computers’ will likely contain a host of other words that are related to Apple computers (such as 'apple stores', 'apple iphone 5', 'apple new ipad', 'apple stock price', 'discount computers').
On the other hand, a keyword-stuffed page about ‘Apple computers’ will probably just contain that one keyword.
So LSI keywords provided Google with a way to sort the sheep from the goats.
But there’s another reason Google started using LSI keywords…
Latent Semantic Indexing helps Google to better understand the meaning of a search query and the meaning of a web page.
And that allows Google to improve the match between what people search for and what they find in the search results.
3. Hummingbird and LSI Keywords
In August of 2013 Google introduced the Hummingbird algorithm, sometimes called the semantic algorithm.
The Hummingbird algorithm focuses on synonyms and improves Google’s ability to understand the context of a web page.
Hummingbird is particularly interested in searcher intent.
Whereas previous algorithms focused on individual words in a search query, Hummingbird looks at each word within the context of the whole search query.
In other words, the Hummingbird algorithm is trying to understand meaning – it helps Google match user intent with search results.
But how does this help me rank higher in the search results?
4. How Can LSI Keywords Improve Your Ranking?
Here are three ways LSI words will improve your SEO:
- Google is now looking at total context rather than keyword density. This means your page will rank higher for your main keyword because Google better understands the context of your page.
- Let’s say you’ve reached the limit for keyword density on your page – anymore repetitions of your keyword and you risk a Google penalty. With LSI keywords, you can safely keep adding closely related keywords.
- LSI keywords are closely related to your main keyword - they're 'keyword variations'. That means your page is going to come up in the search results for your main keyword as well as for those keyword variations.
5. Where To Find LSI Keywords?
Here are some free tools for finding LSI keywords:
5.1 Google Search
Just type in your main keyword and Google will bold any LSI keywords related to your main keyword.
Here’s an example:
My main keyword is ‘lavazza coffee machine’.
In the first search result, Google bolds the main keyword but it also bolds an LSI keyword: ‘espresso’.
Go through each of the results and look for keywords in bold…
…they’re all LSI keywords and you should add them to your page.
5.2 Google Auto Suggest
As soon as you start typing a search query into Google, Google's Auto Suggest function suggests a number of terms that people also search for that are related to your search term.
These are LSI keywords - Google's algorithm has identified them as words that cluster together with your search term in predictable patterns:
5.3 Google's 'Searches Related To'
After you've typed in your search term, scroll to the bottom of the Google results page and you'll see a heading 'Searches Related To':
Here you’ll find some more LSI keywords:
- espresso maker
- a modo mio
Add these to your page as well – they’ll help you rank higher for your main keyword and help you get found for closely related keywords.
Then scan through the results to find LSI keywords to use on your page:
NicheLaboratory will give you a list of related keywords.
You’ll need to use some human judgment to decide which of these are actually related in meaning to your main keyword:
5.6 SEOPressor plugin
Styling itself as “Revolutionary Google-Emulating On-Page SEO Analysis” SEOPressor plugin inlcudes advanced LSI analysis.
It contains two features that will help you with your LSI keywords:
- the ‘Progressive LSI Keywords Engine’ and
- the ‘SemantiQ Density’ analyzer
5.7 Ultimate Keyword Hunter
Ultimate Keyword Hunter is downloadable software that specializes in finding LSI keywords.
It's free but is currently only available for the Windows platform.
6. How To Use LSI Keywords?
Sprinkle them throughout the body of your article, as long as it sounds natural and appropriate.
Some of your LSI keywords will be synonyms for your main keyword – in that case you can just substitute them for your main keyword.
Of course, you’ll need to keep at least 2 or 3 instances of your main keyword.
But don’t worry too much about the keyword density of your main keyword since keyword density has been largely replaced by semantic indexing.
Here are the main places you should use your LSI keywords:
- Page title
- H1 and H2 tags
- URL address
- META tags
- Images alt text
- First paragraph of text
- Links anchor texts
- Last paragraph of text
7. What To Avoid With LSI Keywords
As with your main keyword, try to avoid over-optimizing your page for any particular LSI keyword.
Overusing an LSI keyword will put you in keyword stuffing territory and attract a Google penalty.
I use each LSI keyword just once on a page.
So what are LSI keywords and how can you use them to rank higher in the search results?
Use LSI keywords to avoid keyword stuffing.
Use them to improve your SEO when you daren't repeat your main keyword anymore.
If you write any blog post of more than 1500 words you'll inevitably use LSI keywords because that's what LSI is all about - detecting natural (as opposed to optimized) content.
So the main thing with LSI keywords is keep it natural - use each one only once or twice and make sure it doesn't sound contrived.
And then watch as your pages rise through the SERPs.