More than a third of the visits I look at now come from a phone, and on some sites it is past half. That number keeps climbing every quarter, and yet the average site audit I read still treats mobile as a footnote at the end. A paragraph that says “the site is responsive” and then moves on.
Responsive is a starting point, not an answer. A responsive theme tells you the layout reflows. It says nothing about whether the page is usable on a train with two bars of signal.
Here is what I actually check when I sit down with a site and my phone.
Speed on a real connection. Desktop tools test on fat pipes. I throttle the connection to something closer to 3G and see how long the thing takes to become useful. Not “loaded” in the technical sense, but the point where I can read and tap something. Big hero images and a stack of blocking scripts turn a two second page into an eight second one, and people leave well before then.
What Googlebot sees versus what I see. If a site serves a stripped separate mobile version on an m-dot subdomain, the two can drift apart badly. Content that exists on desktop can vanish on mobile without anyone noticing. I fetch both and compare. Webmaster Tools has a Fetch as Google option that is worth ten minutes of anyone’s time here.
Tap targets and forms. This sounds trivial until you try to complete a checkout with your thumb. Links crammed together, a phone number that is not click to call, a form with a dropdown of 200 countries and no keyboard support. None of that shows up in a crawl. You find it by using the site badly, on purpose, the way a distracted person would.
Redirects and faulty equivalence. A classic one is every mobile URL redirecting to the mobile homepage rather than the mobile version of the requested page. Someone shares a product link, a phone user taps it, and lands on the front page with no idea where the product went. Crawlers flag the redirect but not the fact that it points somewhere useless.
Interstitials. App install banners and full screen overlays that cover the content the moment you arrive. Annoying on desktop, close to hostile on a small screen.
None of this needs an expensive tool. It needs someone willing to hold a phone and actually use the site for ten minutes with the patience of a normal human being, which is to say not much. Most audits skip that step because it does not fit neatly in a spreadsheet. That is exactly why it is worth doing.
