I am planning to build a website completely in Flex. What type of SEO can be done on it? Is it crawlable?
Building a Flex (Flash) based website has always been the bone of contention between website designers and SEO professionals. While website designers argue that it provides great interactivity and a chance to explore the boundaries of creativity (which is quite true), SEO professionals contend that it is not search engine friendly. This scenario was greatly altered when Adobe announced that it is working with Google and Yahoo to enhance indexing of Flash file formats (SWF). This information was echoed in a post made on Google Webmaster Central Blog; a major shift in how search engine treated Flash based websites.
But the picture is not as ‘rosy’ as it may seem. While search engine spiders, especially Googlebot, are capable of indexing flash (SWF) files, it is far from perfect. Jill Whalen made a perfect case out of it – Are The Search Engines Really Indexing Flash?
So “Is it crawlable?” – I would have to say both Yes and No for an answer. It would depend on how you would place content within Flash (SWF) files. Anything that is static will be indexed by search engines whereas anything that is fetched dynamically will not be indexed.
Search engine spiders are interested in data that is present on the webpage and do not care much about the surrounding markup. In case of Flex, the primary source of content is XML (dynamic content) and therefore ‘may’ not be indexed. The common workaround to this issue is XSLT, which can be used to transform XML data into various formats like HTML that can be readily indexed by crawlers. This is how far I can take you with my technical ‘know how’. I would recommend you read Flash & Search Engines : Indexed in a Flash, a mega post that deals with all aspects related to Flash websites.
Once you have digested all the information provide above, I am sure you would have a fair bit of idea on where your website would stand from an SEO perspective. Personally, I would recommend that you use Flash in moderation; search engine spiders are still best at crawling (X)HTML architecture. It would ensure that you website has enough ‘food’ for crawlers. For parts of website built in Flash, I would recommend you refer to this detailed post on beu blog, to make it as search engine friendly as possible.