Hashtags, the keywords preceded by the “#” symbol, are widely used on social media platforms like Instagram to categorize content and increase its visibility. While their primary function is to help posts reach broader audiences, a study in the International Journal of Web Based Communities shows that hashtags also play a significant role in shaping how users perceive the trustworthiness of the post’s source. This research challenges the common practice of “hashtag stuffing”, the use of excessive or irrelevant hashtags to boost engagement. It then explores the unintended consequences it may have on the credibility of a given post and the person or company using them.
On Instagram, as with other platforms, hashtags are often used to tap into trending topics or relevant themes, enabling users to increase the visibility of their posts. This study suggests that beyond increasing visibility, hashtags play a significant role in how users judge the credibility of a post.
Ye Han and Peter Haried of the University of Wisconsin-La Crosse, La Cross, Wisconsin, Shuang Wu of Rowan University, Glassboro, New Jersey, USA, carried out experiments and found that hashtags act as “heuristic cues.” In psychological terms, a heuristic is a mental shortcut people use to quickly make decisions or judgements without having to analyse every piece of information. In this context, hashtags serve as cues that shape how trustworthy a post seems, even if the viewer does not scrutinize the content itself in detail.
When a post includes hashtags, users tend to assume that the source is more likely to share additional information or similar content. This perception increases the post’s credibility, reinforcing trust. However, this trust is undermined when hashtags are deemed irrelevant or excessive, as is the case with hashtag stuffing. Users may begin to question the authenticity of the post, leading them to engage in more critical analysis of the content, ultimately reducing the post’s perceived trustworthiness.
This finding underscores a critical tension for Instagram users, particularly commercial enterprises and so-called influencers who all rely on visibility and reach. While using more hashtags may help posts reach a wider audience, the study suggests that excessive or irrelevant hashtags can backfire. Users may interpret such posts as less credible, as the hashtag choices can signal an attempt to manipulate engagement rather than offer valuable or pertinent content.
The research also suggests that the visual nature of Instagram posts affects how users interact with hashtags. If the image is clear and straightforward, users are more likely to engage with hashtags, trusting that the content is well-supported by relevant tagging. In other words, hashtags should be directly related to the post’s content to maintain both trust and engagement. This balanced approach prevents users from feeling overwhelmed by irrelevant information and ensures a more authentic connection with the audience, the research suggests.
Han, Y., Wu, S. and Haried, P. (2025) ‘The hidden impact of hashtags on Instagram: navigational heuristics on source trustworthiness’, Int. J. Web Based Communities, Vol. 21, Nos. 1/2, pp.155–185.