Keyword density is the number of times your focus keyword occurs on a web page, compared to the total text of that page. If you write a post for your blog, you should have thought about what keyword you want to rank that post for. In our Yoast SEO plugin, that keyword is what we call the focus keyword. If you have a text that is 100 words and 5 of those are your focus keyword, your keyword density is 5%. Is it that black and white? In a very strict world, that would indeed be the case. But Google is smarter than that. In this post, we’ll discuss a number of things you need to take into account when checking keyword density for your pages.
Keyword density in Yoast SEO
In Yoast SEO free, we encourage you to aim for a keyword density of 2.5%. If 2.5% of your post is your desired focus keyword, your text will still be fairly natural to read. It won’t look over-optimized. The thing is, that in the end, you want to make sure your text is written for humans, not Google. If the keyword density of your text exceeds 5%, it will already start to look a lot like spam, or what we call keyword stuffing. It’ll start to look like it’s written for search engines more than your human visitors. Just don’t do that. This is why a keyword density of 2.5% is a nice indication of natural, yet optimized text as well.
Multiple keywords
Often, you’ll find yourself optimizing a text for more than one keyword. Especially long pages or articles can be used perfectly for multiple keywords. It’s usually hard to write two or three articles about similar keywords, so it makes sense to group these. Think along the lines of:
- “SEO” and “search engine optimization”
- “Review” and “Testimonial”
But also words that are a tad bit more unrelated. You might find yourself writing about a “forest” and want to include “trees” as well, for instance. The plural of a word is also something you could add as a focus keyword for your page.
Did you know that adding multiple keywords is a breeze in Yoast SEO Premium? You can add up to 5 (!) focus keywords instead of the single keyword you are used to in our free plugin! Get Yoast SEO Premium here.
When talking about keyword density, SEO and search engine optimization obviously mean exactly the same. Therefore, you should take this into account when checking keyword density for your post. If the keyword density for SEO is already at 2.5%, it would be unwise to add another 2.5% for search engine optimization. You are probably wondering how to check if Google considers two words the same or not: that’s simple. Google one word, and see if the other one is bold as well:
In this example, it’s clear that Google treats “SEO” the same as “search engine optimization”.
Synonyms
We’re so excited to let you know that synonyms are coming to Yoast SEO Premium! In one of the upcoming releases, we’ll allow for synonyms to be used to accompany your focus keywords. So, that means that besides the actual focus keyword, we’ll also let you to insert a number of synonyms, and we will adjust the keyword density calculation accordingly.
Imagine you are writing about forests. You might also want to use the word ‘woods’ to refer to the same thing. You can set ‘forest’ as a keyword and ‘woods’ as a synonym. In addition, you can also use the synonym field to add the plural ‘forests’. To set multiple synonyms, just separate them with commas.
Note that this does differ from the multiple keywords option. That option allows you to optimize for totally different words, whereas we will take the synonyms into account for keyword density and other checks in our plugin. For instance, synonyms are also used when we calculate topic distribution (more on that below).
Keyword versus topic
The terms we use in our plugin to refer to these checks, will differ, depending on which version of Yoast SEO you use. We’ll use the terms ‘keyword density’ and ‘keyword distribution’, as long as you don’t have Yoast SEO Premium and the synonyms feature. As soon as you have that feature, we will no longer refer to the ‘keyword’, but to the ‘topic’, being the keyword and the synonyms, when checking density and distribution. That brings us to the next new feature in Yoast SEO Premium: topic distribution.
Topic distribution
We will also add topic distribution to Yoast SEO Premium in that release! This is actually something we’ve been planning to add for a while. We can tell you that your page has 2.5% keyword density, but if your 2,500 words article uses your focus keyword and synonyms 62 times in just the first two paragraphs, your text will still look strange, right? If your article is about ‘plugins’, you’ll want to use that word throughout the article, not just at the beginning or end. That is why topic distribution is so important.
Just to be clear: we’re talking about topic distribution when you have included synonyms because we calculate the distribution of keywords as well as synonyms. When you don’t have synonyms, we simply calculate the keyword distribution for your keyword or keyphrase.
Keyword density is the basis
You’ll understand by now that keyword density is the basis of how well your post or page is optimized for a certain focus keyword. Keyword density, in our plugin or in one of the many tools available on the internet, will tell you if you’re over-optimizing your text or just not optimizing it enough. If you want to take it a step further and get closer to how Google sees your copy, synonyms and topic distribution will definitely be something to take into account too. Now go optimize!