A word or phrase preceded by the hash symbol (#) used on social media to label content by topic, turning it into a clickable link that groups related posts and makes them discoverable.

How many hashtags should you use?

Relevance over volume. A few specific, relevant hashtags that match the content and the searching audience beat a wall of generic or irrelevant ones, which bury the post or read as spam and can hurt reach.

What is a branded hashtag?

A unique, ownable hashtag a brand creates to gather user-generated content, track a campaign, and turn participants into amplifiers — effective when it's memorable, easy to spell, and genuinely worth using.

Growth Marketing Glossary

Hashtag

hash·tagnoun

The # that turns a word into a clickable topic label — grouping posts, joining conversations, and making content findable. Powerful in moderation, noise in excess.

Schematic — a # label grouping content by topic

Term: Hashtag
Is: A # -prefixed keyword tagging social content
Does: Groups posts; aids discovery
Caveat: A few relevant beats many irrelevant

Parts of speech & senses

hashtag · noun

A word or phrase preceded by the hash symbol (#) used on social media to label content by topic, making it a clickable link that groups related posts and aids discovery. "The campaign rallied around a single branded hashtag."

What a hashtag is

A hashtag is a keyword or phrase written with a # in front and no spaces (#growthmarketing) that turns the word into a clickable, searchable label on social platforms. Tapping a hashtag shows a feed of other posts using it, which means hashtags do two jobs: they categorize content by topic, and they make it discoverable to people who follow or search that topic rather than the account.

Hashtags began on Twitter and spread across Instagram, TikTok, LinkedIn, and beyond, with each platform giving them slightly different weight. They are how a post reaches beyond an account's own followers into topic-based discovery, and how movements, campaigns, and conversations get a shared, findable banner.

How to use hashtags well

The discipline is relevance over volume. A few specific, relevant hashtags that match the content and the audience searching for it beat a wall of generic, high-competition tags (where a post is instantly buried) or irrelevant ones (which read as spam and can hurt reach). The best hashtag strategy mixes scope: broad topic tags for reach, niche tags for relevance, and sometimes a branded or campaign hashtag the brand owns and can rally activity around.

Branded hashtags are a distinct play: a unique, ownable tag (#ShareACoke-style) that gathers user-generated content, tracks a campaign, and turns participants into amplifiers. The discipline there is making the hashtag memorable, easy to spell, and genuinely worth using — and watching it carefully, because an open hashtag can be hijacked or turned against the brand.

Where hashtags help and where they don't

Hashtags matter most where discovery is topic-driven and the platform surfaces them — strong on Instagram, TikTok, and X for reaching new audiences; weaker where the algorithm relies more on engagement signals than tags. They suit content people actively search or follow by topic; they do little for content discovered purely through the feed algorithm.

The recurring mistake is treating hashtags as a magic reach button — stuffing posts with them, reusing the same block on everything, or chasing trending tags unrelated to the content. Used as relevant, intentional topic labels, hashtags extend reach into the right audiences; used as spam, they signal low quality and can suppress it.

Worked example. A brand stuffs every post with thirty hashtags — every trending and generic tag it can find — assuming more tags mean more reach. Instead, posts get buried instantly in the flood of high-competition tags, the irrelevant ones read as spam, and the platform quietly suppresses the reach. Switching to a tight, intentional set — a few specific topic tags that match the content and the audience searching for it, plus one branded campaign hashtag worth rallying around — the brand reaches the right people, gathers user-generated content under its owned tag, and grows engagement. The lesson: hashtags are relevance labels, not a volume lever — a few that fit beat a wall that doesn't. (Illustrative; RGM analysis.)

Failure modes to watch. Stuffing posts with too many or generic high-competition hashtags (instant burial); using irrelevant or trending tags unrelated to the content (reads as spam, can suppress reach); reusing the same hashtag block on every post; treating hashtags as a guaranteed reach button; and launching a branded hashtag that's hard to spell or not worth using.

Synonyms & antonyms

Synonyms

#hashtagtopic tagbranded hashtag

Antonyms

untagged postkeyword stuffing

Origin & history

The hashtag was proposed by Chris Messina on Twitter in 2007, borrowing the '#' (hash) symbol long used in computing to mark labels, to group related messages. It spread across social platforms and entered everyday language as the symbol of topic-based online conversation.

Etymology: source.

Usage trends

Search interest for this term over the last five years:

View interest-over-time on Google Trends →

Common questions

What is a hashtag?: A word or phrase preceded by the hash symbol (#) used on social media to label content by topic, turning it into a clickable link that groups related posts and makes them discoverable.
How many hashtags should you use?: Relevance over volume. A few specific, relevant hashtags that match the content and the searching audience beat a wall of generic or irrelevant ones, which bury the post or read as spam and can hurt reach.
What is a branded hashtag?: A unique, ownable hashtag a brand creates to gather user-generated content, track a campaign, and turn participants into amplifiers — effective when it's memorable, easy to spell, and genuinely worth using.

Resources & people to follow

referenceRGM analysis — definitions, senses, and usage verified per term

Curated, non-competitor resources verified per term.

Related training

moduleGrowth marketing foundations

Disciplines

Areas of marketing where hashtag is a core concern:

Growth strategyPerformance marketing

Sources

trendsGoogle Trends — "hashtag"