Keyword Density is analysed when carrying out Search Engine Optimization (SEO) and measures the percentage of keywords in relation to the content on the page, in the coding, in a URL or in the anchor text in links pointing to your website. The usual formula for keyword density is ‘the number of times a keyword appears in a string of text divided by the number of words within that page multiplied by 100′.

So the keyword density for the keyword ‘density’ in the paragraph above is the number of times the word ‘density’ appears, which is ‘2′ divided by the number of words in the paragraph, which is ‘70′. So that is ‘2 divided by 70 multiplied by 100′ which equals a keyword density of 2.86%. 

So what should keyword density be? Well that depends on certain aspects, the most common being which search engine you are targeting, followed by where the keyword is located (several areas listed above). Keyword density is most commonly analysed in website content.

Your website needs to be readable by your visitor. It needs to flow so that your visitors can read it. If your keyword density is too high it may be unreadable or it may trigger a spam alert in a search engine which may actually lower your ranking. As a result, the first paragraph may look like this:

Keyword Density refers to the density of a keyword. Keyword density is used in SEO. Keyword density measures the percentage of keywords (density) in relation to the content on the page. Keyword density may also be analysed in the URL. Anchor text and inbound links also require keyword density analysis. The keyword density formula is ‘keyword appearances (density) / total keywords x 100′.

So, lets check the keyword density for the keyword ‘density’ in the paragraph above. The number of times the word density appears is ‘9′ divided by the number of words in the paragraph, which is ‘62′. So that is ‘9 divided by 62 multiplied by 100′ which equals a keyword density of 14.52%. This is a great improvement over the first paragraph, but the downside is that it is difficult to read, the keyword density is high enough to trigger a spam alert in a search engine and you may loose visitors as they would rather read someone else’s article which makes more sense.

Therefore it is also important to target only a few keywords per page. For example if you are selling books (this is a nice topic), then you would target the keyword ‘dean koontz’ to the page which lists books written by Dean Koontz. Likewise, you would target the keyword phrase ‘deepak chopra’ to the page which lists books by Deepak Chopra for sale. And so on. Ultimately it is best to target only one to two keyword phrases to one page of your website. And that targeted keyword phrase should have the highest density on that page. However, as mentioned above that does not mean that a high keyword density is good. It must be low enough so as not to trigger a spam alert.

Some websites may come into problems here. An example would be a shopping cart page which lists only the title of the book along with the Author and the price of the book. If we go back to our Dean Koontz example, lets list a selection of books:

• Dean Koontz, The Face, $19.95
• Dean Koontz, Life Expectancy, $19.95
• Dean Koontz, The Taking, $19.95
• Dean Koontz, Velocity, $19.95
• Dean Koontz, The Husband, $19.95
• Dean Koontz, The Good Guy, $19.95

The main problem here is that Dean Koontz has very short titles of the books he writes, often consisting of only one or two keywords. The keyword density of the keyword phrase ‘Dean Koontz’ in the list above is ‘(6 x 2)/30 x 100′ which comes to 40%. Note that we have multiplied the number of appearances of ‘dean koontz’ by two as this keyword phrase consists of two keywords. A keyword density of 40% is a spam alert waiting to happen.

The fact is that issues such as this affect many websites without them even trying to rank highly. This is very unfortunate for some websites where spammy tactics are used without knowledge of them even existing. Therefore, being aware of Search Engine Optimization and implementing it from website build is very important and should therefore be added into the cost of a website. Unfortunately this is often not the case due to additional expenses and, as a result, Search Engine Optimization often involves repairing errors made in the past to conform with search engine algorithms (the formula used by a search engine to determine the ranking of a website). You can see from this, also, that as search engine algorithms change, so too must SEO strategies, to conform with new search engine standards. This means that SEO is not simply a one time fix. Just as when Microsoft release a new version of Windows to make it more powerful and feature rich, you may also need to upgrade your hardware (or buy a new computer) so that you can use this new software.

So, Yes, keyword density is highly important. It is the difference between 1st position and last.

See more factors that affect Search Engine Optimization on our website.