Google will start ranking sites by their mobile version in September

Google will start indexing all websites by their mobile versions beginning in September. Google was already using mobile-first indexing for new domains, but this change will apply the phone-friendly indexing to all domains.

The shift has been years in the making, and Google says that 70 percent of sites shown in search results have already embraced mobile-first indexing. Between now and September, it will continue moving sites to mobile-first indexing when its systems recognize that they're ready.

Google started experimenting with a mobile-first index that ranked sites based on their phone-friendly pages in 2016, and the company made most of its searches mobile-first in 2018. By 2019, it was indexing new web domains as mobile-first by default. This is the natural next step.