Hashtag: what it is, how to write it and how to use it well
The # tag that organizes social media: how to write it, how many to use and mistakes to avoid
A hashtag is a word or phrase preceded by the # symbol, such as #EmailMarketing, that groups together all the social media posts about the same topic. When you tap it, you see everything that has been posted with that tag.
In Spanish, you can say etiqueta, which is the alternative recommended by the Fundación del Español Urgente (FundéuRAE). Even so, “hashtag” is the most widely used word.
What does hashtag mean?
The word comes from English and combines two terms:
- Hash: the English name for the # symbol. In Spain it’s called almohadilla; in much of Latin America, numeral or gato.
- Tag: a label.
So hashtag means “a tag with a hash symbol.” It’s spelled with an h after the s: hashtag, not “hastag” or “hastack.” It’s one of the most common mistakes when people search for it.
Where does the hashtag come from?
On August 23, 2007, designer Chris Messina proposed on Twitter using the # symbol to group conversations. At first the social network ignored him, but users started using it.
In 2009, Twitter turned hashtags into links. Then they spread to Instagram, Facebook, LinkedIn, TikTok and YouTube. Today, hashtags are part of the language of the internet.
How do you type the # symbol?
It depends on the device and the keyboard language:
| Device | How to type # |
|---|---|
| Windows computer (Spanish keyboard) | Alt Gr + 3 |
| Windows, with the numeric keypad | Alt + 35 |
| Mac (Spanish keyboard) | Option (⌥) + 3 |
| English keyboard | Shift + 3 |
| Android phone or iPhone | Tap “?123” or “123” and choose # |
After the symbol, type the word or phrase without spaces: #DigitalMarketing.
Take your campaigns from social media to email
Announce your hashtags to your entire list and connect your newsletters with your social profiles. Free for up to 80,000 emails a month.
How to write a hashtag correctly
A hashtag only works if it follows a few simple rules:
- No spaces. All one word: #BlackFriday, not #Black Friday.
- No punctuation marks. A period, a comma or a hyphen cuts it off.
- Not just numbers. #2026 doesn’t work on many networks; #Sales2026 does.
- Capitalize the first letter of each word. #EmailMarketing is easier to read than #emailmarketing, and screen readers pronounce it correctly.
- Short and clear. If it’s hard to read, nobody will use it.
Accents and the letter ñ work, but #campaña and #campana are different hashtags. Choose one form and always use it the same way.
| Social network | How many to use | Note |
|---|---|---|
| Up to 5 | Since December 2025, it doesn’t allow more than 5 per post | |
| TikTok | 3 to 5 | Mix broad and specific topics |
| 3 to 5 | Professional terms work best | |
| X (formerly Twitter) | 1 or 2 | The text is short: don’t fill it with hashtags |
| 1 or 2 | They’re used less than on other networks |
Except for Instagram’s limit, these are common recommendations, not rules. What matters is that each hashtag is related to what you post.
Branded. They include your company name or your own slogan. They help you gather what’s posted about you and strengthen your branding.
Campaign. They’re created for a specific promotion or launch, such as #SummerWithGreenStore.
Topic or industry. They describe what the post is about: #Marketing, #Recipes, #Travel. They help you reach people who don’t follow you yet.
Event. They group what’s posted about a trade show, a conference or a webinar.
Trending. These are the topics of the moment. Only use them if your post is genuinely related to them.
In an email, hashtags aren’t links: if you write #Sales in your newsletter, nobody will be able to click it. Even so, email helps you bring them to life:
Announce your campaign hashtag in your newsletter so your subscribers use it when they post.
Ask your customers to share photos with your branded hashtag. That user-generated content (UGC) can come back to your emails as social proof.
Use your own hashtag at your events. Include it in the invitation and in the reminders, as we explain in email marketing for events.
Common hashtag mistakes
Using too many. A post full of hashtags looks like spam and is harder to read.
Using unrelated hashtags. Jumping on someone else’s trend gives you visibility for a day and erodes trust in the long run.
Not checking what it means. Before launching a campaign hashtag, search for it: it may already exist with a different meaning.
Writing extremely long phrases. Nobody will remember #ThisIsTheBestDealOfTheYearForYou.
How Mailrelay helps you
With Mailrelay, you connect your newsletters with your social networks. You add your profile icons with the drag-and-drop editor and announce each campaign’s hashtag to your entire list. In the statistics, you can see how many clicks your emails drive to each network.
The free account includes up to 80,000 emails a month and 20,000 contacts, with human support in English on all plans.
Your social networks and your newsletter, working together
Drag-and-drop editor with social icons and click statistics, with human support in English on all plans.
These are the most common questions.
What is a hashtag?
A word or phrase with the # symbol in front of it that groups posts about the same topic on social media.
How do you spell it: hashtag or hastag?
Hashtag, with an h after the s. It comes from hash (the # symbol) and tag (a label).
How do I type the # symbol on the keyboard?
On Windows with a Spanish keyboard, Alt Gr + 3. On a Mac, Option + 3. On a phone, on the symbols screen.
Since December 2025, a maximum of 5 per post. Choose the hashtags that best describe your content.
How do you say hashtag in Spanish?
Etiqueta. The # symbol is called almohadilla in Spain and numeral or gato in Latin America.