One of the more common mistakes for a writer who is just beginning to learn about Search Engine Optimization (SEO) techniques is to get a little carried away with keywords. While nailing down the perfect keyword or keyword phrase is an essential part of landing a higher rank on search engine results and driving traffic to your content, using those keywords too many times in an article is a great way to get moved right down the scoreboard. This is because search engines avoid sites that try to game the system with keyword abuse by ignoring content with an unnaturally high keyword density. Therefore, figuring out the range of ideal keyword density can be critical to an article getting noticed.

The context of an article is not understood by bots indexing web content or searching for keywords. Instead, the content is scanned for the particular pattern of letters contained in the keyword search. The search engine will count how many times a keyword appears within the content and take that into consideration when assigning a page rank. Since designers are aware that people have abused this system by simply using the keyword as much as possible, any content containing a percentage of the keyword in the text compared to the rest of the content, or keyword density, that is above a certain threshold may end up being largely ignored.

Although there is much contention regarding ideal keyword density, a good range for an SEO-optimized article is between 1 to 5%. That may sound low to some, but the leading search engines like Google, start making the cut at 2%. In my opinion, keyword stuffing cuts into the quality of the content at right about 2 to 3% anyway. That’s already 8 to 12 times in a 400-word article.

For some topics, maintaining the ideal keyword density can be easier said than done. For example, I recently wrote a series of articles on carnivorous plants that needed to be search engine friendly, but there aren’t many synonyms for the term ‘carnivorous plant.’ Although I tried to come up with some creative alternatives on my own, I instead decided to launch a more specific SEO keyword strategy. Rather than writing for searches of “carnivorous plant,” I altered my topics for longer keyword phrases such as “aquatic carnivorous plants” or “largest carnivorous plant .” With this change in approach, I had no problem maintaining a decent keyword density for article-optimized keywords that would be more likely to score high on search engines in the first place.

SOURCES:
http://www.webconfs.com/over-optimization-article-8.php
https://ezinearticles.com/?Keyword-Density—How-Much-is-Too-Much-For-SEO?&id=4239978