Hashtags are searchable keywords. If you haven’t been using them in your post, your visibility and engagement per post is not optimized.
Using hashtags gives your post a better chance of being shown to more users, outside of your normal followers. Instagram’s algorithm uses a few factors to determine how visible, and whether they are going to show your post to more people.
Timing is everything, Instagram will promote post that are relevant to the time, so hashtags that are getting a lot of interest are going to be made more visible.
Hashtags also allows potential followers to find your post by searching for keywords that share their interest.
Place your hashtags in the first comment. By putting hashtags in your first comment it keeps the image caption clean and clear. If you are going to place hashtags in the caption make sure they are core hashtags to your post.
Hashtags cluttering your caption can be visually distracting and take away from whatever your caption might be saying. Additionally having long captions filled with hashtags can make reading and interacting with comments less enjoyable.
You are allowed to use up to 30 hashtag per post total, but that doesn’t mean you need to use all 30.
The life of a post being visible is usually short lived, and after a day or so you may wish to remove the hashtags. Placing the hashtags in the first comment allows you to just delete it after their work is done.
Have you hashtags ready. Hashtags being so time sensitive you want to immediately add them to you first comment within seconds of putting up a new post.