Google has published a new page on which Google explains how Google renders web pages for indexing.
Googlebot uses a web rendering service (WRS) that is based on Chrome 41 (M41). Generally, the WRS supports the same web platform features and capabilities that the Chrome version it uses. However, there are a few exceptions and differences that you should keep in mind.
Features and APIs that are explicitly disabled or limited
1. The web rendering service and Googlebot don’t support WebSocket protocol
Googlebot and WRS only understand HTTP/1.x and FTP, with and without TLS. Use the website audit tool in SEOprofiler to check the HTTP version of your website:
2. The web rendering service disables some interfaces and capabilities
- IndexedDB and WebSQL interfaces are disabled.
- Interfaces defined by the Service Worker specification are disabled.
- WebGL interface is disabled; 3D and VR content is not currently indexed.
If you want to find out if Googlebot’s web rendering service supports a certain block of code, use feature detection.
3. Googlebot and the web rendering service are stateless across page loads
Googlebot’s web rendering service loads each URL of your page, following server and client redirects, just like a regular browser. However, the web rendering service does not retain state across page loads:
- Local Storage and Session Storage data are cleared across page loads.
- HTTP Cookies are cleared across page loads.
If a page on your website requires a cookie that was set by another page on your website, this won’t work.
4. The web rendering service declines permission requests
There is an easy way to check your pages
Making sure that Googlebot can index your web pages can be a complicated and time-consuming task. Fortunately, there is an easy way to check your pages. The website audit tool in SEOprofiler checks all pages of your website and it also shows you the things that you have to change so that Google can index your web pages correctly.
When you get an okay from the website audit tool in SEOprofiler, you can be sure that Google and other search engines can index your pages. If you haven’t done it yet, check your pages now: