YouTube has now started highlighting content-relevant hashtags above video titles allowing users to quickly jump from one video to a similar video based on a common hashtag. It's currently unclear when these hashtags started getting greater visibility on video listings, although the feature seems to be active on both the web version of YouTube and in the Android app. It's not yet available on iOS, according to Google.
To be clear, not all videos on YouTube are showing hashtags as the feature is completely dependent on the content creator having included at least one hashtag in the video description in the first place – as it is here where the above-title hashtags are populated from. Therefore videos void of any hashtags by the owner will not show any above the title. The easiest way to see the new feature in action is to search YouTube using a hashtag. At which point any video that does surface in the results should by definition display the highlighted hashtags – as shown above and below.
Considering this change is now live, and in spite of the lack of an official announcement about it, the YouTube Help page section has now been updated with a new hashtags page that reflects the feature. Here, it's noted viewers can now search for content by clicking on a hashtag "above a video title" as well as via the hashtags that appear in the description, or even in the title itself – as these will now be clickable links. Likewise, the help page also points out that although content creators can add a number of hashtags to a video's description, only the first three hashtags listed will be shown above the title. With the suggestion being content creators will want to make sure the first three hashtags are the most relevant or useful to ensure visibility. Before assigning tags, however, content creators might want to check through the "use policies" on the same help page which details a number of the "don'ts," such as using misleading or unrelated hashtags, adding too many (the limit is set at 15), or any that may prove offensive to some viewers.