Using hashtags is a great way to help other users find your content on Instagram, just like on Twitter. Hashtags can include letters and numbers, but they can’t contain any non-numerical symbols (#SocialMediaMarketing might work as a hashtag, but #Social&Media does not, for example.)
Because users can both search for hashtags and click on hashtags they see in posts in the app, using relevant hashtags can be a highly effective tool for getting noticed. However, just like on Twitter, you have to make sure you’re using the right hashtags for your brand — and that you don’t go overboard.
Hashtags such as #nofilter (a photo that hasn’t been heavily edited with filters added), #selfie (a picture of yourself) and #tb or #likeforlike (old photos) are all incredibly popular on Instagram, but they may not work for you or your brand. It’s a good idea to look at other established brands (or even personal users and bloggers) in your industry for examples of what to do when it comes to hashtags.
Instagram allows a maximum of 30 hashtags in a post or comment, but using that many would be excessive. The fewer hashtags you can use to get quality responses, the better. Using a lot of popular hashtags might earn you a lot of likes from other users, but it probably won’t increase your following all that much, and the interactions you get will likely not be from people who are interested in your brand, but rather those who just saw and liked your image.