1. Semrush
  2. Blog
  3. SEO
  4. Technical SEO

12 SEO HTML Tags You Need to Know

Author:Sydney Go

20 min read

May 7, 2024

Contributors: Shannon Willoby and Bartłomiej Barcik

What Are HTML Tags?

HTML tags are pieces of code you add to webpages to provide context to search engines. They help search engines determine what your site is about.

HTML stands for hypertext markup language. It’s the language used by websites.

Tags are also used to structure content. And define how it should be displayed in a web browser. They’re helpful for search engines. And humans.

HTML tags are enclosed in angle brackets ( < > ) and typically come in pairs—an opening tag and a closing tag. The opening tag indicates the beginning of an element. While the closing tag indicates the end of the element.

For example, here’s what a meta description tag looks like in the source code:

Meta description tag shown in the HTML code of a Semrush article.

And here’s what a meta description looks like on Google:

Meta description of the first result in Google Search Engine Results Page.

A title tag tells search engines that a specific phrase is the title of the page.

Here’s what it looks like in the source code:

Title tag shown in the HTML code of a Semrush article.

And here’s what it looks like to web visitors:

Title of a Semrush Article on a green background.

Why Are HTML Tags Important for SEO?

HTML tags are beneficial to your website. And visitors. Here's how:

Structure

HTML tags help you organize and format your content.

This includes:

Search engines can better interpret and index your content with HTML tags.

Understanding

HTML SEO tags provide context to search engines about the purpose of different elements on your page.

By using relevant tags like <title>, <meta>, and <alt>, you help search engines understand the topic and purpose of your content.

Readability

HTML tags structure content visually for web visitors and search engines. Clear headings, bullet points, and well-formatted text make your pages easier to read. And help keep users engaged.

Keyword Optimization

HTML tags allow you to specify important keywords and phrases related to your content. Search engines can use these keywords to determine the relevance of your page to specific search queries.

12 Essential SEO HTML Tags and Attributes for Your Website

Let’s discuss the most important HTML tags for SEO. And user experience.

1. Title Tags <title>

A title tag is an HTML element used to specify a webpage's title. It’s displayed on search engine results pages (SERPs) as a clickable link.

Title tags are important for user experience and SEO. They provide a concise description of the page. So searchers know what to expect when they click through. And help search engines understand the content.

Here’s what a title tag looks like in the SERP as a clickable link:

Title tag of a Semrush article as it appears in the Google Search Engine Results Page.

The tag is also displayed in the user’s browser tab.

Title tag of a Semrush article in the tab area of Google Chrome.

To add a title tag, use the attribute <title> in your HTML builder.

Add an opening <title> tag before the text you want to show as your title. And a closing </title> tag at the end of it.

Title tag HTML code of a Semrush article shown using the Google Chrome Inspect tool.

Your content management system (CMS)—like WordPress or HubSpot—might automatically create your <title> tag once you add a title to your webpage.

Title Tag Best Practices

2. Meta Descriptions <meta description>

A meta description is another HTML meta tag for SEO. It’s a short description of your webpage that can be displayed on search engines. And some social media previews.

Meta descriptions are tags that provide a brief explanation of the content of a page. They often appear below the title tag on SERPs.

While meta descriptions aren’t a ranking factor, they can impact your click-through rate (CTR). And bring people to your site. An enticing meta description can increase the likelihood of users clicking on your link.

Tools like Yoast and Rank Math make it easy to add meta descriptions without having to update the HTML.

A meta description code snippet looks like this in the HTML:

<meta name="description" content="Learn how to develop a tone of voice for your brand and use our template to get started.">

The name=”description” element signifies the type of metadata you’re providing (a description).

The content=” element is where you add a description of what your webpage is about (inside the second pair of quotation marks).

This is what a meta description looks like on search engines:

Meta description shown in the top result of a Google Search Engine Results Page.

Meta Description Best Practices

By writing a meta description that intrigues the searcher, you may get more traffic to the page. Improving the CTR.

Here are some best practices:

Yoast’s plugin looks like this:

Yoast SEO plugin showing the “SEO title” and “Meta description” fields in Wordpress.

3. Header Tags <h1> to <h6>

Header tags, like <h1>, <h2>, and <h3>, help you define each heading and subheading on a page. And help you structure content on all types of pages. Including your homepage, service pages, product pages, blog posts, and more. To make it easier for visitors to read and understand.

They also help search engines understand the hierarchy and context of the content.

The larger the heading size (H1 > H2), the more important it is to include a keyword or descriptive phrase.

Since headings have the potential to be more important than plain text (they help indicate page structure), you should optimize them with keywords when possible.

In HTML markup, the following header tags are common:

header tags structure

For example, H1 tags tell search engines what a page's main topic is. And organize the content clearly. They also show visitors that the page has the information they're looking for.

Here’s what an H1 looks like in HTML:

Heading 1 tag shown in the HTML code of a Semrush article.

And here’s what it looks like to a visitor:

Heading 1 tag as shown to users when visiting a Semrush article.

To add a heading 1 tag in the HTML, you’d use the opening <h1> at the front of the heading. And a closing </h1> at the end.

Many CMS automatically create an H1 from your webpage title. And allow you to easily select headers (like H2s, H3s, and H4s) from the editor without having to update the HTML.

H2s introduce each primary section on a webpage or blog post.

Heading 2 tag as shown to users when visiting a Semrush article.

H3s come after H2s. Use them to organize content underneath an H2. And improve readability.

H3s appear smaller in text size. Indicating subsections within your H2.

Heading 2 and Heading 3 tags as shown to users when visiting a Semrush article.

In a CMS like WordPress, use the editor to choose header tags.

Drop-down menu of the heading option in Wordpress Block Editor.

4. Image Alt Text <img>

Alt text, or alternative text, is a description that corresponds to an image. If the image won't load, the text displays in place of it. The text is also helpful for those who use screen readers.

Here’s an example of an image HTML tag:

<img src="https://example.com/.pixel-7-pro-camera-barjpg" alt="The back of the Pixel 7 Pro showing the aluminum camera bar">

“Img src” indicates the image source. And (alt) indicates the image's alt text.

Here’s what alt text looks like when an image fails to load:

Alt text of a broken image as shown to users when visiting a blog post.

Image alt text is important for SEO because it provides search engines with information about the image's content. Which can help improve the page's relevance.

Optimizing your images can also drive traffic and improve your chances of ranking.

Every image you add to your website is an opportunity to strategically add keywords and phrases. Further optimizing your content for search engines.

In many CMS, you can apply alt text without using an HTML editor.

Tip

Semrush’s SEO Writing Assistant will remind you to add alt text for your images. And help you optimize and improve your content.

Semrush SEO Writing Assistant tool showing the “Add alt attributes to your images” issue.

5. Canonical Tags <canonical>

A canonical tag allows you to specify the preferred version of a page when multiple versions of the same page exist.

For example, let’s say you operate an ecommerce site. Each color variant of the same product has a unique URL. But the content is the same on each page. Use canonical tags to indicate which URL you prefer Google to index.

Canonical tags are important for SEO because they help prevent duplicate content issues. Which may negatively impact rankings. Search engines can understand which version of a page to index and display in search results.

These tags tell search engines which page version (known as the “canonical URL”) it should index. As a result, repetitive content won’t display in search results. And any page authority will go to the canonical URL you designated.

canonical URL (right) and alternate URL (left)

To add a canonical tag, use the code snippet:

<link rel="canonical" href="https://example.com/preferred-url-here/" />

A canonical tag has several attributes:

In some CMS, like Versoly shown below, you can add a canonical URL without accessing the HTML editor.

“Canonical URL” field in the “SEO” tab of the Versoly content management system.

Search engines might index the wrong page if you don’t use a canonical tag. This means you might not rank as highly as you could for your preferred page.

6. Robots Meta Tag <meta robots>

You might not want search engines to index every page of your site. Combining robots meta tags with directives like “noindex” or “nofollow” helps search engines crawl and index your site optimally.

A robots meta tag is a page-level tag that tells search engines and website crawlers how to crawl your site.

Use the robots meta tag to specify whether a page should be indexed by search engines. And whether links on the page should be followed.

Common pages where you might include this tag include:

As an example, you might include the following code snippet in your HTML header if you don’t want search engines to index a page:

<meta name="robots" content="noindex">

The two attributes are “name” and “content.”

You can also use multiple instructions within the content attribute. Such as noindex, nofollow, and noimageindex, among others. Use a comma to separate each one.

Here’s an example of using multiple instructions:

<meta name="robots" content="noindex, nofollow">

The noindex directive tells search engines not to include the page in search results. The nofollow directive tells crawlers not to follow the links on the page.

7. Schema Markup

Schema markup is a type of structured data you can add to the source of a page to help search engines understand the content.

Site owners often use this data to provide additional information about the page. Such as product details, reviews, ratings, and much more.

Here’s an example of markup on the Semrush homepage:

Schema markup HTML script code of the Semrush homepage.

While schema markup isn’t technically an HTML tag, it’s still valuable. It can help improve the visibility and relevance of your page in search results. So it stands out with rich snippets.

Common rich snippet formats include but aren’t limited to:

No matter your business type, using markup can enhance your content's appearance in the SERP and improve your click-through rate. People are more likely to notice and click on the listing.

Let’s say you operate a bakery, and your website has a section for recipes. By adding schema markup for a recipe page, the search results for your recipe pages can display differently than standard organic listings. In the markup, you can include details like ingredients, prep time, and cook time.

Here’s what rich snippets for recipes look like:

Rich snippets of birthday cake recipes as shown in the Google Search Engine Results Page.

Use Google’s Structured Data Markup Helper to add schema markup.

Open the tool. Select the snippet type you want to create, and enter your page URL. Then, click “Start Tagging.”

For this example, we’ll create product-structured data markup.

Google Structured Data Markup Helper with the “Products” option selected and the Apple Macbook Pro URL in the search bar.

The tool will populate the webpage’s URL into the “Tag Data” view:

Google Structured Data Markup Helper tool showing the “Tag Data” view with the Apple Macbook Pro page as an example.

This example is a product snippet for MacBook Pro. So, we’ll include elements like the product’s name, price, image, brand, logo, etc.

Choose or highlight page elements, and the tool will ask you to tag them.

For example, to add the product’s name, highlight it and tag it with “Name.”

Google Structured Data Markup Helper tool with the “Name” option selected in the drop-down menu.

If you wanted to add the price, you would highlight and select the “Price” tag:

Google Structured Data Markup Helper tool with the “Offer” and “Price” options selected in the drop-down menu.

As you work, the tool adds all the information to the right-side panel.

Tag as many elements as you can.

Then, click the red "Create HTML" button at the top-right of the screen.

Google Structured Data Markup Helper tool with an arrow pointing to the “Create HTML” button.

The tool will create a structured data markup code in the side panel.

Google Structured Data Markup Helper tool with the JSON-LD HTML Markup script highlighted.

Finally, copy or download the code and add it to your page's <head> section.

That’s it. You successfully added schema markup.

8. Table <table>

A table tag is an HTML element used to create tables on webpages.

While adding tables to your content may not sound like a typical SEO tactic, you can use them to organize and display data in a structured format. This can enhance the look and feel of your content. Making it easier to read.

Use table tags to create rows and columns (tables) inside your content to present data in a structured and visually appealing manner.

For example, this Sizely table displays jacket sizes by country. Which is helpful for shoppers.

Sizely International Conversion Chart showing jacket, blazers, and coats sizes by country.

Tables have the potential to appear as featured snippets in Google as well. Which can draw attention. And generate more website clicks.

Sizely International Conversion Chart as shown in the Google Search Engine Results Page as a featured snippet.

If your CMS supports copying and pasting tables from other software like Google Docs or Microsoft Word, you may not need to worry about creating specific tags around your copy.

The key table tags to note are:

An example of this might look like:

<table><tr><th>Header 1</th><th>Header 2</th></tr><tr><td>Data 1</td><td>Data 2</td></tr></table>

In the example above, we did the following:

The output will look different per CMS. Depending on whether you apply themes or custom formatting.

9. Iframe <iframe>

An iframe (or inline frame) is an HTML element that lets you embed an HTML document inside a page. It's like a small window on your page displaying content from another place.

Scenarios where you might use an iframe can include:

Your basic code snippet looks like this:

<iframe src="https://example.com"></iframe>

For example, using an iframe to embed a YouTube video will display the media like this:

Iframe embedded Youtube video as shown to users when visiting a web article.

In a CMS like WordPress, you will have an embed/import button that allows you to add an external component using a URL. Rather than fetching and creating code.

For example, you can add the YouTube video URL instead of creating iframe code.

While iframes can improve the user experience, there are also cons for SEO:

We recommend the following best practices for integrating external content:

Note

Content inside iframes doesn’t get indexed by search engines.

10. List Tag <li>

Did you spot the number of lists used in this blog post?

A list tag turns text into a list. Use these tags to organize information.

When readers scan your content, they are unlikely to read every word. Lists make key points skimmable. And easier to read.

Well-formatted lists may also help with SEO.

Google shows featured snippets when it decides it provides the best user experience. One type of featured snippet is a list. Google may pull these from your content if it thinks you have the best list to support a searcher’s query.

Featured snippet shown as a list in the Google Search Engine Results Page.

Here’s what a list looks like in HTML:

HTML code of a Semrush article showing the list section.

And here’s what it looks like to a visitor:

Bullet point list section of a Semrush article showing the four common types of search intent.

If your CMS supports copy and pasting from document creation tools (Word, Google Docs, Notion, etc.), tags get applied automatically.

Before creating a list using HTML, choose if you want the list to be ordered or unordered.

When writing instructions or a recipe, choose ordered since the user needs to execute the list items in a specific order.

The list can be unordered if the list items don't need to be executed in succession. An example would be a list of recipe ingredients.

For an ordered list, use the tag <ol> before and the tag </ol> after your list tags.

Inside the <ol> tags, include your list items and surround them with <li> tags in your HTML editor.

Your list will look like this in HTML:

<ol><li>First item</li><li>Second item</li><li>Third item</li></ol>

When published on your site, your list will look like this:

  1. First item
  2. Second item
  3. Third item

For unordered, use the tag <ul> to precede and succeed your list tags and surround them with <li> tags in your HTML editor.

Your list will look like this in HTML:

<ul><li>Oranges</li><li>Sugar</li><li>Water</li></ul>

When published, your list will look like this:

Hyperlinks, often referred to simply as “links,” are HTML elements that link one page to another. You can use hyperlinks to help users navigate between pages on the same website. Or you can link to other websites.

Hyperlinks are important for SEO because they help search engines discover and index your content. They also help search engines understand the relationships between different pages.

Hyperlink HTML code is made up of:

When combined, your hyperlink HTML code will look something like this:

hyperlink HTML code

On your published page, a hyperlink looks like this:

Hyperlink highlighted in a Semrush article.

Note

Your website will display hyperlinks based on its theme and formatting. They might be underlined, bolded, or colored differently from the rest of your text.

If you copied linked text from Google Docs or Word, for example, the link may accompany the text when you paste it somewhere else.

You can also use hyperlinks for internal linking. An internal link is a hyperlink that directs a site visitor to another page on your website.

Add internal links to any of your pages. Like your “money pages.” Including contact forms, free trials, and demo requests.

Add a call to action (CTA) to encourage the user to engage further. Like "Sign up for your free trial here."

Call to action (CTA) button example as shown to users when visiting a web page.

12. Open Graph Tags and Twitter Cards

Personalizing for different audiences is crucial for generating engagement from platforms other than search engines.

Open graph tags control how you present webpages on social media.

Every blog post you write will likely get shared on social media. Why not boost its performance so it’s more likely to get a click?

Add a new image, title, or description to encourage different social platform audiences to click on your content.

You may want a webpage to display differently on search engines than it does on Twitter, Facebook, or LinkedIn to get more clicks from specific audiences.

So, while your webpage may look like this on search engines and your website:

Title tag as shown to users when visiting a web article.

It can also look like this on social media. (Note the different title.)

Title of the same web article shared on LinkedIn but with a different title.

Your CMS may have the option to add an Open Graph title without the need to edit HTML code.

“Open Graph Title” option in the Versoly content management system.

If not, add the following example HTML code to create alternative titles, images, and descriptions when sharing content on social media.

<meta property="og:title" content="Insert Your Title Here">

The main attributes in play here are:

Implementing HTML Tags for SEO

You might be using HTML tags without even realizing it. Many CMS automatically apply these tags to your pages.

Follow these best practices to use HTML tags properly:

Here’s an example of strategically using a keyword in alt text.

Image Alt Text example of a Semrush article shown using the Google Chrome Inspect tool.

Tools and Resources for SEO Tag Optimization

Using HTML tags is great for SEO, but the process can take time without the right tools.

Analyze your tags for optimal impact with Semrush’s On Page SEO Checker.

Note

If you haven’t already, set up your domain in the On Page SEO Checker. Use our configuration guide if you need help.

When you’ve completed the setup, you’ll see a dashboard overview like this:

On Page SEO Checker dashboard showing the “Overview” tab.

To find opportunities to optimize tags, click on the “Optimization Ideas” tab. The tool will present ideas for optimizing site pages.

On Page SEO Checker showing the “Optimization Ideas” tab.

To view page recommendations, click on the blue “# ideas” button in the “All Ideas” column.

On Page SEO Checker “Optimization Ideas” tab with an arrow pointing to the “# ideas” button in the “All ideas” column.

Scroll to the content section. Which evaluates the presence of keywords in your tags. It also alerts you if it detects keyword stuffing.

And provides suggestions for fixing tag issues. For example, it might recommend writing a more relevant title tag.

“Content” section of the On Page SEO Checker tool with the “Provide a more relevant title” recommendation highlighted.

Identify HTML Tag Issues

with the On Page SEO Checker

Sign up Now

Common Mistakes to Avoid in SEO Tag Implementation

While HTML tags are helpful for SEO, there are still pitfalls to avoid. Here are some strategies to ensure your efforts don’t hinder your search rankings.

Overusing Tags or Keyword Stuffing

Excessive use of HTML tags—such as multiple title or meta description tags—can harm your SEO efforts. Stuffing keywords in HTML tags is also not recommended. Both cases can make your site appear spammy. And could even turn visitors away.

Solution: Use tags when appropriate to enhance your content. Prioritize readability and relevance over excessive keyword use.

Poorly Optimized Title Tags and Meta Descriptions

Forgetting HTML meta tags for SEO is common. Some CMS will create them automatically—such as title tags—but you still need to optimize them for your brand. And target keywords.

Solution: Write descriptive, keyword-rich title tags that convey the page’s content. Similarly, write keyword-rich meta descriptions that entice people to click.

Ignoring Header Tags

Header tags organize content hierarchically. Ignoring or forgetting them can prevent search engines from understanding the page's structure.

Solution: Use header tags to organize the page's structure.

Check Your Site’s HTML Tags with Semrush

Using HTML tags can help your website rank higher, generate more clicks, and improve your content’s readability.

By following the best practices in this guide, you can use HTML tags throughout your site to offer a good experience to both users and search engines.

Run our free SEO checker to flag common HTML tag issues like missing titles, meta, headings, alt text, and structured data.

For a complete picture of your site's health across every page, use Semrush Site Audit.

Find and Fix HTML Tag Issues

with the SEO Checker

Sign up Now

Share

Author Photo

Sydney Go

Sydney has been creating content for over 10 years. She has been a writer, content manager and coordinator, editor, and strategist. At Semrush, she’s a blog editor who makes sure each article is as accurate, optimized, and helpful as possible.

Try Semrush
Everything you need to win AI visibility and drive SEO success
Start Free Trial
Unlimited access for 7 days
Boost your digital marketing efforts
Get free trial