Google on Main Content Indexing

Google’s Gary Illyes recently shared insights into how content is technically indexed, highlighting how certain errors can negatively affect a website’s crawl budget.

Speaking at the Google Search Central Deep Dive event in Asia—summarised by Kenichi Suzuki—Illyes touched on the idea of “centrepiece content,” explaining how Google identifies key content on a page. He also pointed out that soft 404 errors remain one of the most significant issues preventing proper indexing.

Main Body Content

Gary Illyes from Google has highlighted how seriously the search engine takes the task of identifying the main content on a web page. This idea of “main content” is a familiar one for those who’ve looked into Google’s Search Quality Rater Guidelines, where it’s first explained in the opening section. The guidelines not only show how to locate the main content but also offer a breakdown of what quality content looks like.

According to these guidelines, the main content—or MC—refers to any part of a webpage that directly serves the page’s purpose. This could include text, images, videos, tools like calculators, games, or even content created by users, such as product reviews, articles, or comments. Some sites even have tabs that reveal additional information, like customer feedback, which can also be considered part of the main content.

Titles are also included in the definition of MC. These titles, especially when they appear at the top of a page, play a key role in helping users decide whether to click through. A well-written title that accurately sums up the page content is considered helpful and informative.

Illyes described this core area of a webpage as the “centrepiece content” and noted that it plays a major role in how Google ranks and retrieves pages. This main body of content holds much more importance than text found in the header, footer, or navigation bars.

Kenichi Suzuki, who shared a summary of Illyes’ talk, explained that Google gives the most weight to the main content when determining rankings. Words placed here are far more influential than those elsewhere on the page. If you’re aiming to rank for specific keywords, they need to be placed clearly and meaningfully within the main section of your content.

Content Location Analysis To Identify Main Content

This part of Gary Illyes’ talk is particularly worth paying attention to. He explained that Google looks at the fully rendered version of a webpage to figure out where the content sits, allowing it to give more weight to the words placed in the main content area.

It’s not about spotting where the keywords are, but rather about understanding the layout of the page and identifying which content matters most.

As Kenichi Suzuki shared, Google uses a technique called positional analysis. This means it studies the layout of a page after it’s rendered, noting the placement of words and how important they are based on where they appear. For instance, if a key phrase is moved from a less significant part of the page—like a sidebar—to the main content area, it will carry more weight and have a better chance of helping the page rank in search results.

One useful takeaway from this is the role of semantic HTML. Using proper semantic elements in your HTML helps Google understand the different parts of a webpage more clearly. For example, using tags to define headers, footers, navigation menus, or adverts makes the page structure more obvious. This approach is part of a technical SEO practice called disambiguation, which aims to reduce confusion about which parts of the page are most important.

3. Tokenization Is Foundation Of Google’s Index

With the widespread use of AI tools today, many SEO professionals are now familiar with the idea of tokenisation. Google also applies this process, turning words and phrases into a format that machines can understand and use for indexing. Instead of storing the original HTML content, Google saves a tokenised version of the page in its index.

4. “Soft 404s Are A Critical Error

This section is key because it highlights soft 404s as a serious issue. A soft 404 occurs when a page that should return a 404 error instead responds with a 200 OK status. This typically happens when a missing page is redirected to the homepage in an attempt to preserve PageRank, or when it’s sent to an error page that still returns a 200 OK—both of which are incorrect behaviours.

There’s a common misunderstanding among SEOs that a 404 error needs to be fixed immediately. However, a 404 is only problematic if the broken link is meant to direct users to a live page that still exists. If a page has been removed with no replacement content, then a 404 status is actually the correct response. On the other hand, if the original content has been moved or replaced, then a redirect to the new page is appropriate.

What’s important here is that Google treats soft 404s as major errors. So, when SEOs try to “fix” a 404 by pointing it to the homepage, they’re actually introducing a more serious problem.

As Suzuki summarised from Illyes’ explanation: a page showing an error message or lacking meaningful content but still returning a 200 OK status is seen by Google as a soft 404. These pages waste crawl budget and deliver a poor experience, and Google’s systems are designed to detect and ignore them. Interestingly, Illyes even mentioned that Google’s own soft 404 help page was, for a time, flagged as a soft 404 and couldn’t be indexed properly.

Takeaways

Primary Content Focus
Google places the most value on the main content section of a webpage. While Gary Illyes didn’t directly mention it, using semantic HTML can be beneficial in making it clear which areas of a page hold the key information and which parts are supplementary.

Google Uses Tokenisation for Indexing
To better understand content and search queries, Google applies tokenisation — a method that converts text into a format its systems can process. For SEO, this means exact-match keywords are no longer the only path to visibility. Instead, it encourages site owners and writers to concentrate on creating user-focused, topic-relevant content.

Soft 404s as Serious Issues
While soft 404s are often seen as minor nuisances, they actually represent a significant problem for search visibility. These errors can waste crawl resources and hinder proper indexing, which is why it’s crucial for site managers to address them correctly.