In SEO, keyword frequency refers to the number of times a specific keyword or keyphrase appears on a given web page. In other words, keyword frequency is the total number of times the same keywords or keyphrases are repeated on a page.
When you’re done reading this article, you’ll notice that there are specific keywords that appear several times. If you count the number of times the same keywords are repeated, the sum is the keyword frequency for that particular keyword in this article.
If your keyword frequency is too low for your primary or secondary keywords it will be hard for you to rank high on the SERPs (Search Engine Results Pages), unless the competition is low.
If your keyword frequency is too high it sends a negative signal to the search engines, which could label your site as spam. Repeating the same keyword multiple times within a narrow space is often referred to as “keyword stuffing”.
In a worst-case scenario, the punishment of keyword stuffing is getting de-indexed, which means that the search engines remove you from the search result pages.
Keyword frequency is often confused with keyword density, which is related but not the same topic.
In short, keyword density refers to the number of times a keyword appears within a block of content on a web page (product page, blog post, etc.), as a percentage or ratio of the total word count.
So if you have 100 words in an article, and the word “SEO” is mentioned 10 times, your keyword density for “SEO” on that single page URL is 10%.
There are no clearly defined rules about keyword frequency nor keyword density. You can find different guidelines about keyword frequency from various SEO experts. There are even SEO tools, like Yoast SEO, which tell you if your keyword frequency is too low for your primary keywords. Yoast is awesome, especially for WordPress users (which I no longer use, but have in the past).
However, don’t become a slave to an SEO tool. When it comes to using keywords, my rule of thumb is to use common sense — although I realize that can be a dangerous suggestion.
Don’t try to game system, because it’s a game you won’t win. Don’t produce content with the primary goal of stuffing your page with keywords. It’s a losing strategy. Focus on producing quality content for your products and services, that match what people are searching for.
If you do that, you’ll automatically add enough keywords and phrases to make the search engines consider your webpage relevant, without compromising quality.
That said, when you’re in post-production for an article or product page you just wrote, it doesn’t hurt to consider if some sentences can be restructured in a way that both makes it easier to read, and pleases the search engines. Sometimes that means adding your primary keywords a few more times — sometimes it means removing a few keywords (uh oh!).