モバイルファーストインデックス

The phone version is the version

Most searches happen on phones, and Google's index is built mobile-first: what your site shows a phone is what gets indexed and ranked. A desktop-only site isn't penalized; it's simply evaluated through its worst experience.

Mobile rendering starts with one tag: the viewport meta. Without it, phones render a zoomed-out desktop page with unreadable text.

What this site measures

The viewport meta tag and its configuration, fixed-width viewports (which defeat the purpose), and responsive CSS signals such as media queries in the delivered page.

How to improve

• Add <meta name="viewport" content="width=device-width, initial-scale=1">.
• Use responsive layouts (flexbox/grid with breakpoints), not a separate m-dot site.
• Keep tap targets ~44px and base font sizes 16px or larger.
• Test the actual pages on an actual phone; emulators miss real-world jank.
• Make tables and wide content scroll inside their container, not the whole page.

Common mistakes

Popups that cover the whole screen on mobile (Google penalizes intrusive interstitials). Fixed 980px layouts from an old template. Hover-only navigation that touch can't open.