1. Glossary
  2. Content Marketing
  3. JavaScript, Java, AJAX & Flash


For a long time, search engines found it very difficult to read any information and links which do not appear in HTML format within a page’s source code. This applied predominantly to interactive or multimedia content, though not exclusively so. The continuing development of Google Image Search, which is becoming integral to the search engine’s algorithms, has improved this somewhat.

The advent of HTML5 means that websites are able to integrate multimedia content into their basic coding without sacrificing crawlability. Consequently, this has led to some sites phasing out their use of tools such as Javascript, Java, AJAX and Flash, seeing HTML5 as a replacement for them. However, recent tests have suggested that Google has also improved its capacity to crawl content contained in these dynamic formats.
These technologies can be aesthetically beneficial to a website, offering eye-catching content in a format that goes beyond simple text. However, it is important not to overuse them and couple them with relevant, well-researched onsite copy which can be crawled by Google’s spiders.

Javascript and Java

Despite their extremely similar names, Javascript and Java are not actually related to each other. The former is generally embedded on pages (for example, Javascript is important to how Facebook comments are submitted) and has become more visible to search engine crawls, with spiders now even able to follow link redirects set up in Javascript.

However, including too much Javascript is detrimental to search engine rankings, and some web crawlers are unable to index pages which contain information coded that way. Therefore, all links or redirects should be revealed in simple HTML format, and content should not be hidden behind “Read More” icons.

Java, on the other hand, is a more complex coding language, which has many more discrete functions than Javascript. Without including keywords in the alt text of a Java console, as you would for an image, you render the content totally invisible to search engines. It is also possible to include an HTML transcript of your Java page’s text content, much like including a transcript of an audio file, for the sake of improved search visibility.


AJAX raises even greater problems, as it changes content on a page without changing the page’s URL. Consequently, search engines are unable to index it. Google had developed a way to crawl AJAX-enhanced pages in 2009, but ceased recommending the use of AJAX in 2015, although tests have shown that Google is still able to crawl these pages. In order to be certain that your site will be comprehensively crawled while still featuring AJAX, your agency will be able to build new URLs for the differing versions of your content, and conduct standard redirects to them from other areas of the site using standard HTML.


Flash once lived up to its name: Its eye-catching animations were an immediate way to grab a user’s attention. Unfortunately, using Flash also gives your website minimal attention from Google. Search engines are unable to ‘guess’ at the content contained in Flash, and as a result, text contained in Flash animations will not rank in search engine results pages.

As search technology continues to evolve, search spiders are beginning to identify some of the content contained in videos and images. Optical Character Recognition (OCR) is already very much in play, allowing spiders to read images contained in un-spiderable content—to an extent.

With the improvements to Google Image Search, Google can also match pictures based upon their content, as opposed to solely relying on alt text or written description. This recognition of increasingly complex shapes and colours is a major step-forward, and the first real evidence of Google’s step away from a purely HTML-reliant search engine.