Mobile First Indexing is Google’s approach of primarily using the mobile version of a website for indexing and ranking evaluation. In other words, Google primarily crawls your site with Googlebot Smartphone and uses the mobile version as the basis.
The history of Mobile First Indexing:
- 2016: Google announced it and testing began
- 2018: It became the default for new sites
- 2020: The broad transition began
- 2023 (September): Completed for all sites; there is no longer a site-by-site transition
Important implications of this approach:
- Content that is not on the mobile version will not rank
- The mobile version’s Structured Data is what matters
- The mobile version’s internal links are what matter
- Images and videos must be loaded on the mobile version
- A page with noindex on the mobile version will not be indexed
Common mistakes:
- Hiding content on the mobile version for a “better mobile experience” (rankings drop)
- Different meta tags between mobile and desktop
- Incorrect implementation of lazy loading on the mobile version (content is not visible to the bot)
Tip: Treat your site as mobile-first. Design, content, Structured Data — everything should be considered mobile first. Regularly check the “Mobile Usability” report in Search Console.