You might already know that Google’s search engine spiders use the Chrome-based browser to crawl and index webpages.

Like most of Google’s proprietary products, the Chrome browser gets tonnes of new updates every year. However, the transition of Googlebot from one version of the Chrome browser to the other happens only after a lot of testing. 

Google on Wednesday announced that starting December 2019, the Google search spiders will  update the Googlebot user agent string with the version of the chrome browser used for fetching and rendering web pages. 

The change in the version of the Chrome browser in the Googlebot user agent string is seen as Google’s effort to move to an evergreen browser. 

Google has provided an example of the current user agent string and the one that you may see after December.

Googlebot User Agent String Now

Mobile:

Mozilla/5.0 (Linux; Android 6.0.1; Nexus 5X Build/MMB29P) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2272.96 Mobile Safari/537.36 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)

Desktop:

Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)

OR

Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; Googlebot/2.1; +http://www.google.com/bot.html) Safari/537.36

Googlebot User Agent Sting After December

Mobile:

Mozilla/5.0 (Linux; Android 6.0.1; Nexus 5X Build/MMB29P) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/W.X.Y.Z Mobile Safari/537.36 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)

Desktop:

Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)

OR

Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; Googlebot/2.1; +http://www.google.com/bot.html) Chrome/W.X.Y.Z Safari/537.36

“In December we’ll start periodically updating the above user agent strings to reflect the version of Chrome used in Googlebot. In the following user agent strings, “W.X.Y.Z” will be substituted with the Chrome version we’re using. For example, instead of W.X.Y.Z you’ll see something similar to “76.0.3809.100”. This version number will update on a regular basis,” says Google in the official blog post. 

Will the Change Affect Rendering of Websites?

Usually, the updated version of Chrome provides better rendering capabilities, especially when it comes to reading JavaScript. It has to be noted that when Google announced the upgrade of Googlebot to Chrome 74, it said the new version supports over 1,000 new features.

Google has also confirmed that the new Googlebot user agent string will be implemented only after intensive testing and evaluation. This will eliminate the major concerns of the website owners. 

Google also cautions sites that still adhere to user agent sniffing as there are chances that the new Googlebot user agent string may have compatibility issues with these sites. Instead, Google recommends websites to use feature detection and progressive enhancement so that any changes to the user agent string will not affect the rendering of the website. 

Some common issues that Google found while evaluating  the new browser for fetch and rendering:

• Pages that present an error message instead of normal page contents. For example, a page may assume Googlebot is a user with an ad-blocker, and accidentally prevent it from accessing page contents.
• Pages that redirect to a roboted or noindex document.