Prepare for mobile-first indexing

Mobile-first indexing means Google predominantly uses the mobile version of the content for indexing and ranking. Historically, the index primarily used the desktop version of a page's content when evaluating the relevance of a page to a user's query. Since the majority of users now access Google Search with a mobile device, Googlebot primarily crawls and indexes pages with the smartphone agent going forward.

Starting July 1, 2019, mobile-first indexing is enabled by default for all new websites (new to the web or previously unknown to Google Search). For older or existing websites, we continue to monitor and evaluate pages based on the best practices. We notify site owners through Search Console once they're seen as being ready. Since the default state for new sites is mobile-first indexing, there's no need to send a notification to new sites.

What this means for your site

Based on what type of site you have, here's what mobile-first indexing means you:

If you have this type of site...
Desktop only: Your site is desktop only and doesn't have a mobile-friendly version. No change. The mobile version is the same as the desktop version.
Responsive web design: Your site adjusts for screen size. No change. The mobile version is the same as the desktop version.
Canonical AMP: All your web pages are created in AMP HTML. No change. The mobile version is the same as the desktop version.
Separate URLs: Each desktop URL has an equivalent different URL that serves mobile-optimized content. This site type is also known as an m-dot site. Google prefers the mobile URL for indexing. To prepare for mobile-first indexing, follow our best practices.
Dynamic serving: Your site serves different content based on the user's device. Users only see one URL. Google prefers the mobile optimized content for indexing. To prepare for mobile-first indexing, follow our best practices.
AMP and non-AMP: Your site has both AMP and non-AMP versions of a page. Users see two different URLs. Google prefers the mobile version of the non-AMP URL for indexing. If your non-AMP mobile version uses dynamic serving or separate URLs, follow our best practices.

Best practices for dynamic serving and separate URLs

If your site has separate desktop and mobile content, which means you have a dynamic serving or separate URLs (or m-dot) site, make sure you follow the best practices below to prepare for mobile-first indexing:

  • Your mobile site should contain the same content as your desktop site. If your mobile site has less content than your desktop site, you should consider updating your mobile site so that its primary content is equivalent with your desktop site. This includes text, images (with alt-attributes), and videos – in the usual crawlable and indexable formats.
  • Structured data should be present on both versions of your site. Make sure URLs in the structured data on the mobile versions are updated to the mobile URLs. If you use Data Highlighter to provide structured data, regularly check the Data Highlighter dashboard for extraction errors.
  • Metadata should be present on both versions of the site. Make sure that titles and meta descriptions are equivalent across both versions of your site.

Additional best practices for separate URLs

If your site has separate URLs (also known as m-dot), there are additional best practices you should follow.

  • Verify both versions of your site in Search Console to make sure you have access to data and messages for both versions. Your site may experience a data shift when Google switches to mobile-first indexing for your site.
  • Check hreflang links on separate URLs. When you use rel=hreflang link elements for internationalization, link between mobile and desktop URLs separately. Your mobile URLs' hreflang should point to mobile URLs, and similarly desktop URL hreflang should point to desktop URLs.
  • Ensure your servers have enough capacity to a handle potential increase in crawl rate on the mobile version of your site.
  • Verify that your robots.txt directives and robots meta tags work as you intended for both versions of your site. The robots.txt file lets you specify which parts of a website may be crawled or not, and the robots meta tags let you specify which parts of a website may be indexed or not. In most cases, sites should use the same robots.txt directives and robots meta tags for both mobile and desktop versions of their sites.
  • Make sure you have the correct rel=canonical and rel=alternate link elements between your mobile and desktop versions.

Changelog

We've announced a lot of updates around mobile-first indexing. Here's a changelog of everything we've announced:

Changelog
May 28, 2019 Mobile-first indexing is enabled by default for all new, previously unknown to Google Search, websites starting July 1, 2019. For older sites, we'll continue to monitor and evaluate pages for readiness, and will notify site owners through Search Console once they're ready.
March 26, 2018 Mobile-first indexing is rolling out more broadly. We published documentation on how to prepare for mobile-first indexing. Content gathered by mobile-first indexing has no ranking advantage over mobile content that’s not yet gathered this way or desktop content.
December 19, 2018 We notify the site owner through Search Console when we move the site to mobile-first indexing. Prepare for mobile-first indexing by verifying that structured data and alt-attributes are on both versions of your pages.
December 18, 2017 We will be evaluating sites for readiness and cautiously rolling out mobile-first indexing for sites that are ready.
November 4, 2016 We are experimenting with making the index mobile-first.