Ajax SEO

AJAX loads content interactively and makes pages faster. For SEO this can be a problem if crawlers only pick up the initial content. Server-side rendering, dedicated URLs for important content and checks in Google Search Console help.

By loading content interactively, AJAX makes websites faster. For SEO, however, AJAX can have drawbacks when it comes to indexing, i.e. when a search engine's web crawler (bot), such as Google's, crawls a URL. Today, the main remedies are server-side rendering and clean, linkable URLs of their own.

What is AJAX?

Asynchronous JavaScript and XML (AJAX) is a technology that loads web content on demand. First, the default view of a web page is loaded. The user sees what the page offers and can choose from various options. If they select one of these options – e.g. another menu item or an info box with further information – (only) this content is loaded. Other options remain unloaded or are also only delivered on request. This makes for fast, smooth usability.

AJAX and SEO: the problems

Since the entire page does not have to be rebuilt, the website responds quickly. And because not all web content has to be transferred on the first load, the initial loading time is also very short. From an SEO perspective, however, this advantage has a downside. When a crawler indexes the web page, it only picks up the content from the initial load. The crawler does not execute the available AJAX requests. As a result, the optional content does not appear in the search engine index after crawling. If, from the site owner's point of view, this happens to be the most important SEO content, that is a problem.

Solutions for AJAX and SEO

There are several ways to get around this problem. Google used to recommend providing an HTML snapshot – a second, static version of the page for the crawler only. Google deprecated this approach in 2015: Googlebot can now execute and render JavaScript itself. However, this happens with a delay and not always completely. It is therefore more reliable to deliver important content directly in the HTML via server-side rendering (SSR) or pre-rendering. Content that is meant to rank also needs its own crawlable URL and must be reachable via normal links – not just via click events.

The URL Inspection tool in Google Search Console lets you check which content Google actually sees after rendering. This way you can spot early on whether dynamically loaded content is missing from the index – especially in shops where filters, variants or reviews are loaded via JavaScript.