A hashtag turns a word or phrase into a clickable, searchable link that collects every public post using it. It helps platforms understand what a post is about and lets people follow or browse a topic. Hashtags are most useful as a categorisation and discovery signal rather than as a reach hack.
Their weight varies by platform and shifts over time. On some networks hashtags meaningfully aid discovery; on others the ranking system leans more on the caption, on-screen text and engagement. Either way, a few specific, relevant tags almost always outperform a wall of generic high-volume ones, which invite spam and rarely convert.
Mix broad, niche and branded tags, keep them genuinely relevant to the post, and consider a branded hashtag to gather user-generated content and community posts in one place. Review which tags actually drive reach and drop the ones that do nothing.