How does Google understand the difference between ‘Apple’ the tech company and ‘Apple’ the fruit?

Or how does search spiders distinguish between ‘It’ the pronoun and ‘It’ the massively-successful horror movie?

The answer is LSI— short for Latent Semantic Indexing.

What is LSI in SEO?

What Are LSI Keywords?

Latent Semantic Indexing is a method used by search engines to identify the relationship and relevancy between the search keys used by people and the entire content on web pages.

How does it identify this relationship?

By looking for closely related keywords or synonyms of the original keywords in individual contents. These synonyms are called LSI keywords.

Okay, let’s make this easier to understand!

LSI Keywords Example

Say you’ve written a post on content writing, titled “How to be a successful content writer?

Now the Google bots will crawl through the post and try to find the relationship between the title and the entire content—and it does this by looking for LSI keywords in the content.

And only then does it sorts your article on Search Engine Result Pages (SERPs) according to the relevancy between the title and post and the search keywords.

When crawling through the article, aside from keywords, it will look for LSI phrases like: content writing tips, what does content mean, content writing services.

Here’s a list of LSI keywords of ‘content writing’ generated by

LSI Keywords Example

Why Should You Get LSI Keywords?

Let’s use 2 scenarios to understand:

#1. There are two articles with the same set of primary and secondary keywords. The keyword density in the article is similar. With DA and other SEO factors put on constant, how will Google decide which one to rank higher on result page?

It will rely on LSI Latent Semantic Indexing keywords to identify which of these 2 articles are more relevant to their titles. And then it will rank them accordingly.

#2. There are two articles on the same topic. They are targeting the same set of keywords. But one has the higher keywords density in the content—although it’s poorer in quality and its main content isn’t directly relevant to its title. 

If it ranks higher just because of its more keywords density, would that not be unfair for the other quality content?

To counter this problem, search engines no more prioritize keywords density. To make sure the content relates the title and is ideal for the search keys used by users, they look for a range of LSI keywords inside it.

How to find LSI keywords? is possibly the best and simplest LSI keywords generator out there.

Other tools include ‘Keyword Shitter’ (yes, you read correctly!) and Keywords Suggestion Tool of The SEO Tools.

Ultimate Keyword Hunter (here) is another popular tool. But it requires you to install it on your computer. I have never used it personally. Try it if you've got time and see if it’s any good.

Another way to get LSI keywords is to look at the Google search result page yourself.

Google your keyword. Scroll down and see ‘Searches Related to *your keywords*’. These are your LSI keywords. Also, through the page, look for bold words in the description of every result.

Know why they are bold? Because these are words that tell Google about the relationship between the title and the entire content, the relevancy between your keyword and the content.

Mark them out too—they are your LSI keywords.

How to find LSI keywords?

How to use LSI keywords?

Just sprinkle them enough throughout your article.

Write your post normally. Once done, when editing and proofreading, put them in sentences wherever they fit.

And now your content is completely ready to do a lot better on Search Engine with just minutes of extra work.

Isn’t that awesome?

Now that you know what is LSI in SEO, go ahead start your research.

Leverage a good latent semantic indexing tool, find suitable LSI keywords and use them throughout your next blog post to get more search engine-love.

READ: How to do Keyword Research for Free in 11 minutes?

For more on content marketing strategy and SEO to boost traffic, follow Spell Out Marketing on Twitter! :)

Asif Ali

Asif is a certified content marketer and professional full-stack writer with 3 years experience in his pockets. Stratightedge, blogger and a full-time cloud-lover, find him on Facebook and Twitter.

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