Javascript, Java, Ajax & Flash

Historically search engines found it hard to read any information and links that do not appear in HTML format within a page’s source code. The continuing development of Google Image Search, which is becoming integral to the search engine’s algorithms, has improved this somewhat.

Javascript and Java

Javascript and Java are not related to each other. The former is usually embedded on pages 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 bad for 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 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 changes content on a page without changing the page’s URL. As a result, search engines are unable to index this. 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.


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.

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