BrainHandles (love the name btw 
) did a little experiment that I have been planning on doing, but haven’t gotten around to. Does Google index words on the page that have been placed there by Javascript?
So far his results are that Google does NOT index words inserted via javascript. He created a page with 2 unique words that were standard HTML on the page, 2 unique words that were displayed via document.write but the javascript was in-page, and finally 2 more unique words that were displayed via a remote js. Only the HTML words are able to be found via the search engine.
This makes sense, though I tend not to assume that google doesn’t use everything they can get their hands on. But it is pretty solid that if the page comes up in the serps for the HTML words he used, then it “should” come up for the JS words he used, IF google is indexing those words. So signs are pointing to “no, google does not index JS”. However, per other experiments I, and others, have performed, google does crawl JS, as well as parse it.
The main reason this is an issue is because of AJAX. If your build ajax sites, you also have to account for engines crawling. How do they get to the relevant data? How do they index your site? If there is no content, how can your site be found via searches? It’s always been a wrench in the AJAX methodology for me, and this just confirms it a bit more I think.
I think i too am going to have to confirm this experiment. I will update if I remember to…
Via: http://www.brainhandles.com/2007/03/11/does-google-index-dynamic-javascripted-content/
