Thursday, January 23, 2014

A new Googlebot user-agent for crawling smartphone content

Webmaster level: Advanced

Over the years, Google has used different crawlers to crawl and index content for feature phones and smartphones. These mobile-specific crawlers have all been referred to as Googlebot-Mobile. However, feature phones and smartphones have considerably different device capabilities, and we've seen cases where a webmaster inadvertently blocked smartphone crawling or indexing when they really meant to block just feature phone crawling or indexing. This ambiguity made it impossible for Google to index smartphone content of some sites, or for Google to recognize that these sites are smartphone-optimized.

A new Googlebot for smartphones

To clarify the situation and to give webmasters greater control, we'll be retiring "Googlebot-Mobile" for smartphones as a user agent starting in 3-4 weeks' time. From then on, the user-agent for smartphones will identify itself simply as "Googlebot" but will still list "mobile" elsewhere in the user-agent string. Here are the new and old user-agents:

The new Googlebot for smartphones user-agent:
Mozilla/5.0 (iPhone; CPU iPhone OS 6_0 like Mac OS X) AppleWebKit/536.26 (KHTML, like Gecko) Version/6.0 Mobile/10A5376e Safari/8536.25 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)

The Googlebot-Mobile for smartphones user-agent we will be retiring soon:
Mozilla/5.0 (iPhone; CPU iPhone OS 6_0 like Mac OS X) AppleWebKit/536.26 (KHTML, like Gecko) Version/6.0 Mobile/10A5376e Safari/8536.25 (compatible; Googlebot-Mobile/2.1; +http://www.google.com/bot.html)

This change affects only Googlebot-Mobile for smartphones. The user-agent of the regular Googlebot does not change, and the remaining two Googlebot-Mobile crawlers will continue to refer to feature phone devices in their user-agent strings; for reference, these are:

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

The two Googlebot-Mobile user-agents for feature phones:

  • SAMSUNG-SGH-E250/1.0 Profile/MIDP-2.0 Configuration/CLDC-1.1 UP.Browser/6.2.3.3.c.1.101 (GUI) MMP/2.0 (compatible; Googlebot-Mobile/2.1; +http://www.google.com/bot.html)
  • DoCoMo/2.0 N905i(c100;TB;W24H16) (compatible; Googlebot-Mobile/2.1; +http://www.google.com/bot.html)

You can test your site using the Fetch as Google feature in Webmaster Tools, and you can see a full list of our existing crawlers in the Help Center.

Crawling and indexing

Please note this important implication of the user-agent update: The new Googlebot for smartphones crawler will follow robots.txt, robots meta tag, and HTTP header directives for Googlebot instead of Googlebot-Mobile. For example, when the new crawler is deployed, this robots.txt directive will block all crawling by the new Googlebot for smartphones user-agent, and also the regular Googlebot:

User-agent: Googlebot
Disallow: /

This robots.txt directive will block crawling by Google’s feature phone crawlers:

User-agent: Googlebot-Mobile
Disallow: /

Based on our internal analyses, this update affects less than 0.001% of URLs while giving webmasters greater control over the crawling and indexing of their content. As always, if you have any questions, you can: