Hashtags

A hashtag is a word or phrase preceded by the hash symbol (#) that users attach to posts on social media to categorize content and facilitate discovery of related material. Hashtags help signal topic, event, or sentiment and enable others to find posts related to a specific theme.

Hashtags originated on Twitter, where they were proposed in 2007 by Chris Messina to group conversations. Since then, their use has spread to many platforms, including Instagram, Facebook, TikTok, and YouTube. The term combines the symbol with the concept of tagging content, and its popularity rests on the ability to create and join topic-driven streams of posts.

Functionally, hashtags are used to organize content, participate in discussions, and track trends. They can support community building around shared interests, amplify campaigns, and aid in content discovery. On many platforms, the visibility and reach of a post can be influenced by the presence of relevant hashtags, though the effect varies by platform and audience.

Usage guidelines emphasize relevance and clarity. Choose hashtags that accurately reflect the content, avoid excessive tagging, and consider readability (for example, using camel case for multiword phrases). Platform-specific practices and limits apply, with some networks supporting only a few hashtags per post and others allowing many.

Limitations and concerns include mislabeling, spam, and attempts to manipulate metrics. Hashtags can reveal sensitive topics or be used to coordinate harassment. Moderation and moderation-heavy topics pose challenges, and users should be mindful of privacy and community norms when employing hashtags.