Google Indexer Rendering JavaScript
Traditionally, we were only looking at the raw textual content that we’d get in the HTTP response body and didn’t really interpret what a typical browser running JavaScript would see. When pages that have valuable content rendered by JavaScript started showing up, we weren’t able to let searchers know about it, which is a sad outcome for both searchers and webmasters.
In order to solve this problem, we decided to try to understand pages by executing JavaScript. It’s hard to do that at the scale of the current web, but we decided that it’s worth it. We have been gradually improving how we do this for some time. In the past few months, our indexing system has been rendering a substantial number of web pages more like an average user’s browser with JavaScript turned on.
