 Hello, and welcome to the JavaScript SEO series. I'm Martin Splitt, a webmaster's trends analyst here at Google. In this video series, we will explain how Google search and JavaScript work together and what that means for SEO. So let's look at how Google crawls and indexes your websites for a moment. It starts by our crawler visiting a web page like any other browser would do. It then passes the content it sees onto the indexing stage. That is where the content is parsed and stored in our index. When links are detected, they are passed back to the crawler and the cycle continues. But what if some of the content is generated by JavaScript? Well, JavaScript requires an extra stage in the cycle, the rendering stage. Googlebot executes JavaScript when rendering the page. But because this rendering stage is expensive, it can't always be done immediately. Separating indexing and rendering allows us to index content that is available without JavaScript as fast as possible and to come back and add content that does require JavaScript at a later time. The web is big, like really, really big. So Google has seen over 130 trillion web pages. Rendering all those pages takes some time. Deferring the execution of JavaScript allows us to get most of the content as quickly as possible while not missing out on the content that does require a JavaScript to be run. But what does that mean for your content? It means that Googlebot can execute JavaScript on your site, but it can take longer for that content to appear or update in search. How long it takes for Google to render your pages depends on many different factors, and we can't make any guarantees here. The rendering stage is run as best effort. If getting content indexed quickly is a concern, check out the episodes on the different rendering techniques and the JavaScript SEO fundamentals episode. It's worthwhile mentioning that JavaScript can be pretty costly. It needs to be downloaded, parsed, and executed, making sure the users get the content as quickly as possible and leveraging the progressive parsing and rendering of HTML is a great way to do so. It's good to keep in mind that while Googlebot can run most JavaScript, other crawlers or social media agents might not be able to do so yet. There are ways you can handle those user agents gracefully, too. We'll go into that in one of the future episodes. We will also explore how to make JavaScript-based websites work well with Google Search, including answering common questions and looking at tools that help your content's SEO. So don't forget to subscribe to our webmasters channel to be notified about our new JavaScript SEO videos. Thank you very much, and see you soon.