Brands are investing heavily in Instagram, increasing the volume of their posts. As a result, most indicators show significant growth since last year: - Brands are publishing 24% more content across all formats. - Average reach is also up, by 7%, from 10,047.31 to 10,706.86. - The frequency of weekly posts has increased by 9% (from 1.19 to 1.30). And it seems this increase in content creation has been accompanied by greater consumption. Overall, views have grown by 27%, and interactions have also increased: by 19%, to be exact. Okay, so all good, right? No. Despite the increase in all of the above, engagement (the percentage interaction rate) is down by 7% (falling from 3.79% in 2025 to 3.54% in 2026). Publishing more content works to increase views and overall interactions, but with so much content available, the engagement rate per post suffers. Furthermore, the overall drop in engagement is mainly due to the decline in single-image posts, as Reels (as we'll see) are evolving in the opposite direction. Reels, the star format on Instagram This 24% growth in the number of posts isn't evenly distributed across all post formats. There's a 12% increase in single-image posts, a 24% increase in carousels, and a 35% increase in Reels. However, the return on this effort varies drastically depending on the chosen format. While Reels and carousels are excellent for gaining visibility, they achieve this through different approaches. Reels stand out for their ability to reach new audiences, increasing their reach by 11.69%. Carousels, on the other hand, stand out in terms of views: Instagram is showing them again to users who didn't initially interact with them, boosting this metric by 53.57%. In terms of interactions, Reels lead the way, generating, on average, four times more interactions than a single-image post and becoming the only one of the main formats whose engagement is projected to increase by 2025. Their engagement rate grows by 24.76%, reaching 4.30%. In contrast, single-image posts see declines of 21.96% in reach, 25.41% in interactions, and 45.98% in engagement. The study also highlights the growth of Reels in key metrics such as shares (+67%), interactions (+32%), likes (+18%), and reach (+12%). Furthermore, the average watch time skyrockets by 118%, even though views only increase by 2%. Metricool explains this by saying that “the algorithm is showing content to those who are truly interested.” Three Days to Shine According to Metricool, two out of every three Reel views and 61% of total interactions occur within the first three days of publication. For single-image posts and carousels, this window narrows even further: they achieve 76% of their views and 75% of their total interactions within those three days. The Curious Case of Hashtags As I mentioned, the study includes many interesting data points about Instagram, but I find what happens with hashtags particularly curious. In just a few years, we've gone from a social network that relied heavily on these tags to one that practically ignores them. According to Metricool, posts that use them register 32% fewer views and 34% fewer interactions than the overall average. The study attributes this decline to the definitive arrival of SEO on the platform: Instagram now directly indexes captions for keyword searches, and even public posts appear on Google and Bing. Therefore, the use of natural language and strategic business keywords matters more than ever, relegating hashtags to a secondary role where it's advisable to include only one or two that are highly relevant and specific to the industry, completely avoiding generic tags.