hi, i want to ask if there is increase or decrease in the ranking if the keyword density of the page is low? and also what is method to increase the keyword density when we have already put our keywords in Alt, metas and content
Yes, Keyword density effects the ranking. However, I think if you properly used Keywords in Metas, Content and Alts, there is no need to add keywords on that page otherwise, it will be called as "Keyword Stuffing"... One thing you can do if you have not done it yet is to add "Abstract" Tag in your Metas...
I have seen pages ranking well for a particular phrase, without actually having that phrase present in the content, but obviously, you want to have your keyword density as high as practical, without affecting the readability of your content. Be careful not to overdo it, or your page may be penalized for keyword stuffing. Mark
Some SE's KW density is a big part in terms of rankings while on other SE's having quality backlinks are the main criteria. It all depends on which SE you are trying to get a rank with.