Instagram SEO keywords: find the words your customers actually use
What are Instagram SEO keywords? They are the ordinary words and short phrases a person types into the Instagram search bar, and that you have written into your caption, so the post can be matched to the search. “Sourdough starter for beginners” is a keyword phrase. So is “wedding photographer Bali”. As of August 2026, Instagram’s own advice to creators is to use descriptive, relevant keywords in captions, because search uses captions as reference data for discovery. The hard part is not placing them. It is knowing which words your customers really use, and the cheapest place to learn that is the captions of posts that already do well in your niche.
This guide shows how to find those words by hand, where each one should go, and how to speed up the collecting step when you do it every month.
The short answer
- Write captions in the words a customer would type, not in brand language. “Hand-poured soy candles” beats “our signature scent collection”.
- Use two or three keyword phrases per caption, worked into real sentences. A pile of words at the end reads as a spammer and gives search nothing extra.
- Put them in the caption, not a comment. The caption is the text Instagram describes as the context for your post.
- Find the words from real posts, specifically popular recent posts under the hashtags your customers browse.
- Keep hashtags as a small second layer. Keywords carry the meaning, and how many hashtags to use explains why five is plenty.
What Instagram says about keywords
Social Media Today reported in August 2026 on a set of caption tips Instagram published for creators. The line that matters here, in Instagram’s words as the article quotes them:
Captions add relevant context, spark conversation, and tell search engines what your content is about: making them a key part of your content strategy.
The same piece reports Instagram’s advice to include descriptive and relevant keywords, since Instagram search uses captions as reference data for discovery. Nothing in it gives a number of keywords to use, a ranking formula or a promise of reach, so treat any guide that does as a guess. What you can act on is simple: your caption is searchable text, so write it as if someone were going to search for it.
Where keywords can go
Captions are the main place, but not the only one. Each spot has a different job.
| Place | What goes there | Example |
|---|---|---|
| Caption, first two lines | The main phrase, in a natural sentence | ”A beginner’s guide to feeding a sourdough starter” |
| Caption, body | One or two related phrases | ”…whether you bake weekly or once a month” |
| Carousel slide descriptions | A short description per image | ”Starter after eight hours, doubled in size” |
| Profile name and bio | What you do and where | ”Maya, sourdough baker in Leeds” |
| Hashtags | Five tags that match the post | #sourdoughbread |
Only the first two lines of a caption show before the “more” link, so lead with the phrase you most want to be found for. It also reads better to a person who is scrolling.
How to find the keywords by hand
You are looking for the phrases real people already use when they post about your subject. Four steps do it.
- List your subjects. Write down five or six things you post about, as a customer would name them. A bakery might write: sourdough, banana bread, birthday cakes, gluten-free, bakery in Leeds.
- Search each one on Instagram. Type it into the search bar and open the top results, then switch to the tag pages for the closest hashtags. Watch what autocomplete offers while you type. It shows phrases people have searched.
- Read the captions of the best posts. Open ten posts that got plenty of likes and comments recently. Copy the nouns and phrases that repeat: “no knead”, “overnight”, “for beginners”, “crusty”. Do not copy sentences. Copy the vocabulary.
- Sort the phrases into a sheet. Three columns: the phrase, how many of the ten posts used it, and which of your subjects it belongs to. Phrases that appear in four or five of ten are the vocabulary of that niche.
Keep the sheet. When you write a caption, pick the phrase that fits the post and use it once near the top.
A worked example
Take a florist in Austin. The subject list is: wedding flowers, bouquets, flower subscription, dried flowers. Reading the captions of well-received recent posts under the matching tags might turn up phrases such as “locally grown”, “in season”, “wedding bouquet”, “same day delivery” and “dried arrangement”.
The sheet shows “locally grown” and “in season” in most of the posts, while “same day delivery” shows up in only a few. So a caption for a new bouquet might open: “A wedding bouquet of locally grown, in season flowers, built around peonies and ranunculus.” One sentence, three phrases, nothing stuffed.
Keywords and hashtags do different jobs
A hashtag puts a post on a browsable page. A keyword in a caption helps the post match a search. They are not rivals, and you do not need to choose.
- Hashtags gather an audience around a topic. They work best when specific and few. If you want to check yours, how to search hashtags on Instagram shows how to read a tag page.
- Keywords describe the post. They work best when they match the phrase a customer would type.
If your current captions are one line plus thirty tags, rewriting the first two lines is the larger change.
Mistakes that waste the effort
- Writing for a robot. “Best cheap coffee Leeds coffee shop Leeds coffee” helps nobody. One clear phrase per sentence.
- Borrowing words that fit someone else. A word that is common in a rival’s captions may describe a product you do not sell. Check that each phrase is true of your post.
- Never looking again. The words people use change with seasons and trends. Redo the sheet every month or two.
- Putting the phrase only in a comment. Keep it in the caption.
- Promising results. No keyword guarantees reach, and your own account’s numbers are the only fair test. Do hashtags still work on Instagram describes how to compare posts fairly.
A faster way to collect the words
The slow step is reading captions one post at a time. If you need the vocabulary of a whole niche, or you want to repeat the exercise every month, Hashtag Ninja can do the collecting. You describe what you want to know in a sentence, such as which words posts under a few wedding tags use in their captions, and it plans a collection of recent posts under those tags, then returns a written report. Each run keeps its rows to download as a CSV with one row per post: the permalink, the date, the caption, the hashtags, the counts and the author handle. That means you can sort by likes, filter to the best posts and read their captions in one sheet instead of ten tabs. The export to CSV page explains the file.
It is free to try with no signup, and the planner at the home page will show you the collection plan before anything runs. The report is a way to find the words faster. Choosing which of them are true of your business, and writing the caption, stays your job.
When the manual way is enough
Do it by hand if you post a few times a week in one niche, if you can name your customers’ words from conversations you already have, or if you are still learning what the niche sounds like. Ten posts per subject and a sheet is a good habit, and it teaches you more than any report will.
A collection tool starts to earn its place when you cover several niches or clients, when you want the same sheet every month, or when you need to compare the language of two audiences side by side. For picking the tags themselves, how to do hashtag research for Instagram walks through the measurements one tag at a time.
Quick checklist before you post
- The main phrase is in the first two lines of the caption, in a real sentence.
- It is a phrase a customer would type, taken from posts in your niche.
- No more than two or three phrases in total.
- Five hashtags or fewer, matching the post.
- Your profile name and bio say what you do and where.
- The sheet of phrases is less than two months old.