Understand HTML to better understand SEO


Part of the brilliance of WordPress is that it makes HTML updates behind the scenes so that users with no coding ability can create “SEO friendly” pages. For example, site owners can install Yoast’s SEO plugin, and update the “SEO title” of their homepage by typing keyword phrases just as they would in a Word document. When they select “Update,” WordPress magically adjusts the HTML <title> element of the page. Google picks up on the HTML change when it crawls the site, and the update becomes visible in search results as one of ten blue titles.

Google bot speaks HTML

Regardless of what language a site is coded in, all forward facing pages are written in HTML. HTML 5 does away with tags that affect style, and relies entirely on CSS instead. HTML is the structural support system of the web, but it doesn’t stop at structure. Search engines parse HTML to gain meaning.

HTML gives clues as to the subject of a page, what’s important on that page, what entity or topic it refers to, who wrote it, whether it’s part of a paginated series, where the business the page describes is located etc. All of this information is gathered by Google as it crawls the web. It is for this reason that Google asks Webmasters to make certain changes to their HTML code depending on the purpose of the page. For example, Google’s search algorithm has been tweaked several times to discourage low quality pages from appearing in search. Even a site that contains a minority of low quality pages can be negatively impacted by Panda across the board. In order to avoid penalizing quality sites that have a number of pages that would be perceived as low quality by a bot, Google uses HTML cues.

Rel=”prev,” rel=”next” is a perfect example.

Rel=”next” Rel=”prev”

Many paginated pages, such as author and category archive pages, contain duplicate content. How? Snippets of the content that appear on the main or canonical page, also appear on the archive pages. Regardless of whether the content is linked through a content management system, the pages are crawled and indexed separately. Marking up HTML with rel=”prev,” rel=”next” allows Google bot to determine that the page it encounters is part of a paginated series, not a duplicate page that has scraped content from another original source. Google actually asks site owners to make these HTML changes where a paginated series occurs.

Yoast’s WordPress SEO plugin is so popular because it allows SEOs to make accurate, global changes to the HTML of niche sections of their site without touching a line of code. The plugin automatically adds rel=”prev,” rel=”next” tags, as well as canonical tags, to a paginated series. Other updates are at the user’s discretion. For example, in the “meta” section, Yoast allows site owners the option of noindexing paginated archives. All category, author and tag archives can be noindexed, or non-canonical pages (everything after page 1) can be blocked to the search engines.

Semantic HTML and Schema.org

In addition to markups that provide information about how pages on a website relate to each other, HTML also helps search engines better understand the subject of a given page, and what the most important elements are. For example, the concept of semantic HTML refers to structuring the content in such a way that a search engine, or visitor, can easily see what the focus is. The style is controlled by CSS, but the <H1> tag of a page is traditionally in large, bold font, and addresses one of the most important issues in the content. As header tags decrease in number, they also should decrease in importance of subject matter. For example, labeling a heading with an <H2> or <H3> send a message that the content isn’t as important as the page title or <H1>. These smaller header tags are often used for sub-categories.

Not all semantic HTML markups are visible to the website visitor. Schema.org is a form of structured data recognized by all the major search engines. Search engines like schema.org because, it adds additional contextual information to HTML. For example, certain types of schemas create “rich snippets” in the search results. Depending on the level of trust associated with your website, marking up a page with Rating schema will cause stars to appear in search results. This has a big impact on click through rates. However, it’s not only schemas that cause rich snippets that add value. Especially in light of Google’s Hummingbird update, and the rise of the semantic web, providing search engines with as much information about a page will help more intuitive search engines make as many connections as possible between topics and entities.

Creation of Google’s data highlighter, which allows structured data to be added without touching code, shows just how much Mountain View wants site owners to use additions to HTML to provide Google bot with more information about content on the web, and how it’s related.

As Aaron Bradley said in this article:

Search engines are going out of their way to get webmasters to feed them structured data, which suggests that they find it useful for reasons other than producing rich snippets…Structured data provides a method of explicitly declaring relationships between things…


Links are nothing more than HTML tags. The HTML code for a link is simple, it looks like this:

<a href=”url“>Link text</a>

Despite link signals becoming heavily polluted by spam, links are still used as indicators of trust and authority by Google. Links act as a votes for useful content, but also as pathways that take us from one document to another. As a New Yorker, I travel through the city in taxis and trains. Google bot crawls the web via links. This is why virtually every SEO ranking factor is measured in terms of links. Links are the doorways through which Google discovers and indexes new information.


Gaining a basic understanding of HTML is helpful to gaining a deeper understanding of SEO. Google doesn’t see websites as visitors do, it sees and reads HTML. Knowing how to modify the HTML of your website can help search engines better understand your site which can correspond into greater online visibility. If you’re not code savvy, using a content management system like WordPress makes creating an SEO friendly site easy.

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