@emelie
There is no universally accepted ideal number of keywords for the meta keywords tag. However, including too many keywords can actually harm your website's ranking and make it look spammy to search engines. It's recommended to keep the number of keywords to a maximum of 10 to 15, and make sure they accurately describe the content on your page. Keep in mind that many search engines, including Google, do not use the meta keywords tag in their ranking algorithms.