When creating a modern web page, there are three major components:
A common use of AJAX is to update the content or layout of a webpage without initiating a full page refresh. Normally, when a page loads, all the assets on the page must be requested and fetched from the server and then rendered on the page. However, with AJAX, only the assets that differ between pages need to be loaded, which improves the user experience as they do not have to refresh the entire page.
One can think of AJAX as mini server calls. A good example of AJAX in action is Google Maps. The page updates without a full page reload (i.e., mini server calls are being used to load content as the user navigates).
As an SEO professional, you need to understand what the DOM is, because it’s what Google is using to analyze and understand webpages.
The DOM is what you see when you “Inspect Element” in a browser. Simply put, you can think of the DOM as the steps the browser takes after receiving the HTML document to render the page.
The DOM is what forms from this parsing of information and resources. One can think of it as a structured, organized version of the webpage’s code.
Headless browsing is simply the action of fetching webpages without the user interface. It is important to understand because Google, and now Baidu, leverage headless browsing to gain a better understanding of the user’s experience and the content of webpages.
Are bots able to find URLs and understand your site’s architecture? There are two important elements here:
The easiest way to solve this problem is through providing search engines access to the resources they need to understand your user experience.
!!! Important note: Work with your development team to determine which files should and should not be accessible to search engines.
Internal linking is a strong signal to search engines regarding the site’s architecture and importance of pages. In fact, internal links are so strong that they can (in certain situations) override “SEO hints” such as canonical tags.
All of these studies are amazing and help SEOs understand when to be concerned and take a proactive role. However, before you determine that sitting back is the right solution for your site, I recommend being actively cautious by experimenting with small section Think: Jim Collin’s “bullets, then cannonballs” philosophy from his book Great by Choice:
“A bullet is an empirical test aimed at learning what works and meets three criteria: a bullet must be low-cost, low-risk, and low-distraction… 10Xers use bullets to empirically validate what will actually work. Based on that empirical validation, they then concentrate their resources to fire a cannonball, enabling large returns from concentrated bets.”
Consider testing and reviewing through the following:
After you’ve tested all this, what if something's not working and search engines and bots are struggling to index and obtain your content? Perhaps you’re concerned about alternative search engines (DuckDuckGo, Facebook, LinkedIn, etc.), or maybe you’re leveraging meta information that needs to be parsed by other bots, such as Twitter summary cards or Facebook Open Graph tags. If any of this is identified in testing or presents itself as a concern, an HTML snapshot may be the only decision.
HTML snapshots are a fully rendered page (as one might see in the DOM) that can be returned to search engine bots (think: a static HTML version of the DOM).
Google introduced HTML snapshots 2009, deprecated (but still supported) them in 2015, and awkwardly mentioned them as an element to “avoid” in late 2016. HTML snapshots are a contentious topic with Google. However, they're important to understand, because in certain situations they're necessary.
When considering HTML snapshots, you must consider that Google has deprecated this AJAX recommendation. Although Google technically still supports it, Google recommends avoiding it. Yes, Google changed its mind and now want to receive the same experience as the user. This direction makes sense, as it allows the bot to receive an experience more true to the user experience.
A second consideration factor relates to the risk of cloaking. If the HTML snapshots are found to not represent the experience on the page, it’s considered a cloaking risk. Straight from the source:
“The HTML snapshot must contain the same content as the end user would see in a browser. If this is not the case, it may be considered cloaking.”
– Google Developer AJAX Crawling FAQs
Despite the considerations, HTML snapshots have powerful advantages:
When browsers receive an HTML document and create the DOM (although there is some level of pre-scanning), most resources are loaded as they appear within the HTML document. This means that if you have a huge file toward the top of your HTML document, a browser will load that immense file first.
The concept of Google’s critical rendering path is to load what the user needs as soon as possible, which can be translated to → "get everything above-the-fold in front of the user, ASAP."
Critical Rendering Path – Optimized Rendering Loads Progressively ASAP:
!!! Important note: It's important to understand that scripts must be arranged in order of precedence. Scripts that are used to load the above-the-fold content must be prioritized and should not be deferred. Also, any script that references another file can only be used after the referenced file has loaded. Make sure to work closely with your development team to confirm that there are no interruptions to the user’s experience.
Read more: Google Developer’s Speed Documentation
Thanks: Thank you Max Prin (@maxxeight) for reviewing this content piece and sharing your knowledge, insight, and wisdom. It wouldn’t be the same without you.