The first 15 MB of HTML content is indexed by Googlebot.
The first 15 MB of HTML content is indexed by Googlebot.
Google's web crawler now only considers the top 15MB of HTML on a website when determining rankings, according to an update to the tool's help page.
The HTML file itself, excluding embedded resources or anything retrieved using IMG tags, is what counts. SEO professionals have wondered whether text appearing below photos at the cutoff would be ignored entirely by Googlebot.
However, Google Search Advocate John Mueller clarified that only the HTML file is considered. This development means that crucial information must be placed at the top of web pages, and code should be arranged to ensure the first 15 MB of any text-based or HTML file contains SEO-relevant data. Whenever possible, images and videos should be compressed instead of being directly encoded into HTML.
The good news is that most websites will not be affected since current SEO best practices recommend keeping HTML pages to 100 KB or less. Additionally, several tools such as Google Page Speed Insights can be used to determine page size.
If your HTML pages exceed 15MB, you may have underlying issues that need to be addressed. Google has stated that the 15MB limit solely applies to HTML files, and photos and videos are acquired independently.
Finally, it is worth noting that this is not a new development, but rather one that hasn't been adequately documented before.