How many keywords can be put in one web page ?

You can put a maximum of 10 but it was better if you can only put 5-6 keywords in every page of your site.

 

There should be 3 to 4 percent in 400 word article

 

I would suggest to go with a single 'key word' and use multiple variations (key phrases) of the same keyword.

This would not only bring a variation within your web page but will also help you to optimize your website on multiple relevant keywords.

Good day,

 

Unless you're already a major authority within your niche, 2-3 per page should be your aim.

Gone are the days when new sites can rank for many keywords per page.

WebDev

 

I'd focus on 2 high-traffic keywords... write a 600 word article/post with a 2% kw-density for those 2 main kw's and see if you can insert some long-tail low-traffic keywords in the content (without it looking spammy), I usually automatically implement related keywords as i write the article.

 

The recent google update has killed the whole "keyword stuffing" thing. The important thing now is just to keep everythign looking naturally. Trying to jam a non natural keyword many times on your page isn't going to look natural to google anymore after their recent updates.