Webmasters usually consider keyword meta tags important for on-page optimization of the website. However, Google doesn’t use the “keyword” meta tags in web search rankings.

This is because Google can sell its search appliance product which could include the keywords meta tag but this is different from web search and therefore it doesn’t gives weightage to keyword meta tags. They simply don’t effect the search ranking in Google at all.

Secondly, earlier search engines judged the content of the pages and not other off page factors such as links that point to the page. So at that time, keyword meta tags became a choice whereby one could stuff irrelevant keyword without typical visitors ever seeing these keywords and this was so abused that Google started disregarding keyword meta tags.

However, Google still use the “description” meta tag as the text for its search results snippets. Even though Google sometimes uses the description meta tag for the snippets it shows, it still doesn’t use the description meta tag in its ranking.

It’s possible that Google could use this information in the future, but it’s unlikely. Google has ignored keyword tags for years and currently there is no change to that policy.