SEO Hashtags

I would start by accepting that hashtags are social metadata, not SEO keywords. Google does not index hashtags in the same way it indexes page copy. If your goal is organic search traffic from Google, a hashtag strategy is a distraction. But if you want social discovery — people finding your post because they followed or searched a hashtag — then a thoughtful approach matters. Here is the path I follow now.

First, I write the caption as if hashtags did not exist. I optimise the caption for keywords that match the search intent of my audience on that platform. For example, if I post on Instagram about [on-page SEO](/on-page-seo/), my caption includes the phrase “on-page SEO checklist” rather than just “SEO”. Instagram’s algorithm now reads caption text heavily. I treat it like a mini piece of [SEO copywriting](/seo-copywriting/).

Second, I choose hashtags based on relevance, not volume. I pick one broad tag (e.g. #SEO), one niche tag (#TechnicalSEO), one branded tag (#Searchpedia), and one location tag if applicable (#BangkokSEO). That gives me four. I test this set for a week, then adjust. I avoid tags with millions of posts where mine will vanish in seconds.

Third, I keep the set tight. For Instagram and TikTok I use 3–5. For LinkedIn I use 2–3. For X I use 1–2. For YouTube video descriptions I use 2–5, but I also place them in the first few lines of the description so they appear in the collapsed preview. I never repeat the same tag in exactly the same form on every post — variation signals I am covering a topic cluster, not spamming.

Fourth, I track what works using UTM parameters on the link in my bio or post. I build a simple spreadsheet that compares reach and click-through for posts with different hashtag sets. I stop using any tag that consistently underperforms after ten posts. This data-driven loop is more reliable than copying a influencer’s list.

The biggest trap is treating hashtags as a replacement for proper content [SEO](/seo-blog/). I have seen practitioners stuff a post with fifteen hashtags and neglect the caption entirely. That is backwards. The algorithm — whether Instagram, TikTok or LinkedIn — now weighs caption keywords, on-screen text and alt text more heavily than hashtags. A 2023 Hootsuite experiment showed that posts without hashtags sometimes outperformed hashtag-heavy posts when the caption was keyword-rich.

Another watch-out: platform rules change. YouTube recently shortened its description preview truncation point. If you pile hashtags at the very end of the description, they may not appear in search results at all. LinkedIn now shows hashtags below the post but does not give them the same weight as topic tags set in the publisher interface. And TikTok’s search recommendations often prioritise on-screen text typed in the video editor over hashtags typed in the caption.

Also watch your brand reputation. Using trending hashtags that have nothing to do with your content is a short-term reach hack that hurts trust. I have seen accounts lose followers after one #MondayMotivation tag on a dry technical post. Context matters.

Finally, never assume a hashtag strategy from one platform works on another. The same set that drives engagement on Instagram may look spammy on LinkedIn. I keep a separate note for each platform’s norms. If you manage multiple accounts, create a simple table of allowable counts and banned tags per platform.

For years I thought more hashtags meant more reach. I added eleven or twelve to every Instagram post, believing the Instagram algorithm rewarded volume. I was wrong. When I cut back to five targeted tags, my engagement rate actually rose by about 15% over three months. The algorithm seemed to value the clarity of a focused topic signal more than a broad scattergun approach.

I also believed hashtags could compensate for weak content structure on my own website. I would write a blog post, sprinkle #SEO and #Marketing into the body, and expect Google to reward it. It did not. Google does not crawl hashtags in the same way it crawls keywords. The real lever for ranking a piece of content is traditional [on-page SEO](/onpage-seo/): title tags, [meta descriptions](/meta-description/), header structure, and internal links. Hashtags in body copy can actually confuse the reader and dilute the keyword signal.

Another mistake: I used the same hashtag set for every post. I thought consistency helped build a brand tag. But it looked robotic. The audience saw the same six tags and ignored them. I now vary at least half the tags per post, keeping only the consistent brand tag (#MyBrand) and one broad category tag.

Finally, I ignored the role of [alt text](/alt-text/) on image-based platforms. Instagram lets you add alternative text. I never bothered. Now I write keyword-rich alt text for every image — it improves accessibility and gives the algorithm another signal. Hashtags alone could not do that job.