Hashtags on Instagram and TikTok: Do They Work and How to Choose Them

A few years ago, 30 hashtags under a post could bring hundreds of new views. Now things are different: Instagram and TikTok understand the content itself much better. But hashtags haven't gone away; their role has simply changed. Here is how to use them today.

Why hashtags matter today

A hashtag is a hint to the algorithm about what your post is about and who to show it to. It rarely brings thousands of people by itself, but it helps to:

• classify your content correctly in recommendations;
• get you found by people searching for the topic;
• gather your posts under a branded hashtag (for example, customer reviews).

How many hashtags to use

• Instagram: 3-5 precise hashtags. More gives no advantage, and irrelevant ones can even hurt.
• TikTok: 3-5 hashtags, plus one trending hashtag if you like, as long as the video is really on that trend.

The main rule: every hashtag must describe this exact post. #fashion under a photo of a cake won't help.

How to choose hashtags

1. One broad hashtag, the topic in general: #manicure, #cakes, #renovation.
2. Two or three niche hashtags, to narrow it down: #gelmanicure, #customcakes, #apartmentrenovation.
3. One local hashtag if you work in a city: #manicureLondon.
4. One branded hashtag, your own: #instahub_reviews.

Where to look for ideas:

• Instagram and TikTok search: see how many posts a hashtag has and whether they are recent;
• hashtags in posts of successful accounts in your niche;
• suggestions in the search field when you start typing a word.

Common mistakes

• The same set under every post. The algorithm may see this as spam. Change hashtags to match the content.
• Banned and "broken" hashtags. Instagram restricts some popular hashtags. Before using one, open it: if only a few posts or a warning appear, don't use it.
• Hashtags instead of substance. The caption and the first frame matter more. Keywords in the caption and in the profile name help search just as much as hashtags.

What works better than hashtags

• Keywords in the caption. Instagram and TikTok index text: "flourless cheesecake recipe" will be found even without a hashtag.
• Subtitles and on-screen text, which the algorithm also recognizes.
• The first hours of activity. A post that immediately gets likes, saves and comments is more likely to reach recommendations. Starter activity or auto-likes on every new post can help here.

For more on what affects video reach, read the article Reels: what really affects reach.