Mobile first

The term is used for two things that are connected. For people who build websites, it means designing for the small screen first and then expanding for desktop. For Google, it means the search engine reads the mobile version of your site when it decides where you rank.

What Google actually says

Google writes that it uses the mobile version of a site's content, crawled with the smartphone agent, for indexing and ranking. Content that only shows on desktop is left out. If you have removed text, images or price lists from the mobile version to save space, they do not count in Google.

Why it makes better sites

Starting with the phone forces priorities. There is no room for everything, so you have to choose what matters most. That usually makes the desktop version better too. Responsive design is the technique. Mobile first is the order you think in.

Compare for yourself

Open your website on a computer and on your phone, side by side. Go through the service pages and check that the same content is in both places, especially prices, opening hours and contact details. If something is missing on the phone, it is missing for Google too. We wrote about the shift when it began, in our 2017 post on mobile-first indexing.