What is keyword density?

What is Keyword Density and how to create a script in PHP?

• I am working on a project where I have to find out the keyword density of thepage on the basis of URL of that page. I googled a lot but no help and scripts were found, I found a paid tool http://www.selfseo.com/store/_catalog/php_scripts/_keyword_density_checker_php_script But I am not aware actually what "keyword Density of a page" actually means? and also please tell me how can we create a PHP script which will fetch the keyword density of a web page. Thanks

• Answer:

  "Keyword density" is simply the frequency that the word occurs given as a percentage of the total number of words. The following PHP code will output the density of each word in a string, $str. It demonstrates that keyword density is not a complex calculation, it can be done in a few lines of PHP: <?php $str = "I am working on a project where I have to find out the keyword density of the page on the basis of URL of that page. But I am not aware actually what \"keyword Density of a page\" actually means? and also please tell me how can we create a PHP script which will fetch the keyword density of a web page."; // str_word_count($str,1) - returns an array containing all the words found inside the string $words = str_word_count(strtolower($str),1); $numWords = count($words); // array_count_values() returns an array using the values of the input array as keys and their frequency in input as values. $word_count = (array_count_values($words)); arsort($word_count); foreach ($word_count as $key=>$val) { echo "$key = $val. Density: ".number_format(($val/$numWords)*100)."%<br/>\n"; } ?> Example output: of = 5. Density: 8% a = 4. Density: 7% density = 3. Density: 5% page = 3. Density: 5% ... To fetch the content of a webpage you can use http://php.net/manual/en/function.file-get-contents.php (or http://php.net/manual/en/book.curl.php). As an example, the following PHP code lists all keywords above 1% density on this webpage: <?php $str = strip_tags(file_get_contents("http://stackoverflow.com/questions/819166")); $words = str_word_count(strtolower($str),1); $word_count = array_count_values($words); foreach ($word_count as $key=>$val) { $density = ($val/count($words))*100; if ($density > 1) echo "$key - COUNT: $val, DENSITY: ".number_format($density,2)."%<br/>\n"; } ?> I hope this helps.