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LSI Keywords vs Related Phrases and How to Use Them for SEO

If you’ve heard the term “LSI keywords” and been confused as to what exactly they are – or what they’re used for- you’re in the right place. 

In this article, we’re going to give you a quick overview of what LSI keywords are and how you can use them to boost your website’s SEO strategy. 

So, without further adieu: 

What are LSI Keywords in SEO? 

LSI, or “Latent Semantic Indexing”, is a specific natural-language processing system designed to associate words with common synonyms. 

Or, put simply, a process that helps machines understand the different ways people might try to express the same concept. 

For example – if you’re looking for a “mouse” how does a computer system differentiate between the mouse you use to interact with your computer and the mouse you’d hate to find in your kitchen? 

LSI is one potential answer to that – by associating the word with the context of the word around it, it can determine which it is. 

For example, if the word “computer” is used on the page the system can assume it’s that kind of mouse. If the page lists animals – it can similarly assume the opposite.

Do LSI Keywords Matter for SEO? 

In short; no.

How do we know that? Well, Google engineers have straight-up said so. To top it off, LSI as a system (dating back to the 1980s) wasn’t designed to handle anything near as complex as the internet. 

But, you might say, Google definitely uses some sort of system to sort through synonyms and polysemic words. 

And you’d be right – just Google the word “mouse” and you can see that the system asks you to differentiate which of the two you meant. 

What do they use then? Well, like most things Google it’s a closely held secret, but it ties into related words and phrases – which definitely do help boost SEO rankings. 

How to Use Related Phrases to Boost Your Website’s SEO Strategy 

Many SEOs confuse the term LSI Keywords, which is a specific technique, with related words and phrases as a general strategy. 

As we’ve covered, LSI keywords aren’t useful for SEO – but using related words and phrases in your website’s content definitely does help SEO. 

It’s unclear exactly how much Google’s algorithm associates related works with one another – but seeing as their goal is only ever to match the way people search, and people do search using these words and phrases, it’s a safe bet to say they matter. 

How to Find Related Words and Phrases  

Before you can start incorporating them into your website – you need to first find the most commonly searched related words and phrases relevant to your business. 

There are a million ways to do this, but here are the easiest methods to start with: 

  • Your own experience. Don’t overthink it – start by just using the words you would logically associate with your business. For example, you know that “keyboards, headphones, speakers, wifi adapters, etc. all are related to “computer peripherals”. 
  • Google autocomplete. If you want to find the words and phrases Google finds most relevant, their autocomplete feature is an amazing (and 100% free) way to start. Simply open up a new, incognito, tab and type in a phrase – then see what Google suggests after (or before) it. 
  • Google’s related searches. There are also always “Related searches” at the bottom of every Google search – another great source of related words and phrases from Google itself. 

How to Use Related Words and Phrases  

If you’re an expert on a given topic, you’re probably already using related keywords and phrases in any content you write. If not, use the research tools above and incorporate them as organically as possible into the content of your website.
Don’t “spam” words or insert them randomly and out of context – this will get you penalised. Think of how you organically switch between topics to incorporate phrases – and go with that.

Conclusion – LSI Keywords vs Related Phrases 

LSI Keywords are an outdated system that is often mistaken for related words and phrases – which are a useful SEO tool to consider when creating content for your business’ website.

Consider how you can organically integrate related words and phrases for your industry into your website; to make it clearer for both users and search engines what your pages are about.
This can create great SEO benefits for many businesses. 


If you enjoyed this article or found it helpful, check out more e-commerce marketing content on the inSyte blog or listen to the inSyte Podcast.

This article was brought to you by Syte.

We’re a specialist e-commerce and lead generation digital marketing agency dedicated to driving up your bottom line.

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