Google has just announced that from the 18th April 2016 it will be replacing the Googlebot User Agent used on Smartphones from iPhone to Android so that they can better understand pages from new web technologies.
Google has in the past regularly updated the user-agents they use for Googlebot, but mostly these reflect an upgrade to the version of the OS (i.e. iPhone OS 6.0 to iPhone OS 8.3) rather than a wholesale change to a different one altogether.
Google confirms that the main reason for the change is that their “Renderer” has evolved over time to be more similar to Chrome, than to Safari. As a result, developers are being advised to check that their websites can be viewed properly by a wide range of different users and browsers, with Google recommending feature detection (checking whether features work in specific browsers) and progressive enhancement.
The old User Agent, based on the iPhone OS, is as follows:
Mozilla/5.0 (iPhone; CPU iPhone OS 8_3 like Mac OS X) AppleWebKit/600.1.4 (KHTML, like Gecko) Version/8.0 Mobile/12F70 Safari/600.1.4 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)
The new User Agent, based on the Android OS, is as follows:
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)
Google believes that 99 percent of all users will be unaffected by the change although if a website looks for a particular Googlebot user-agent string, then the code should be updated on the 18th April. That being said, Google stresses that looking for particular Googlebot User agents is not something they like, as they consider it a form of cloaking. If you are found to be serving different content to Google than to your users, then it is likely to end in a penalty.
After the new user-agent goes live, and you believe you may be affected, then it is worth checking your website with the Fetch and Render Tool in the Search Console.