Keyword density v. keyword frequency

When optimising content for a website, there are three measures to apply to keywords: density, frequency and prominence. Although the three distinctly overlap, they are all treated differently by search engines and should be looked at individually when applying SEO to any text.

Keyword density is the percentage of times that keywords appear within any block of text. It’s a tricky balance: too few and the site doesn’t attract attention, too many and you can get penalised for keyword stuffing. Density is possibly the most controversial of SEO metrics as the optimum figure is not entirely agreed upon by experts, although current general consensus is around 3%.

Keyword frequency is the number of times a certain word is included. This refers to a straight count of the number of words and not a percentage or any other metric. So for example, a keyword may appear five times. In a 100 word text its frequency is five and its percentage is 5%, in a 500 word document, it is only 1%. Similar to keyword frequency, it is finely balanced between attention-seeking and overusing to the point of penalising.

Keyword prominence refers to the positioning of your keywords within the text. The optimum position is to include your keywords within the page title and any meta-tags the site has. It can also help to reiterate keywords within the opening paragraph, sending a clear signal regarding your page topic to search engines, without necessarily compromising on your density or frequency statistics.

The bottom line is always to write your content for your readers, only inserting keywords where there is a natural place for them. There’s no point writing your text with only the search engines in mind if it’s going to be off-putting for readers.