Mobile-First Indexing
Mobile-first indexing is Google's policy of using the mobile version of a page — not the desktop version — as the basis for crawling, indexing, and ranking. After experiments starting in 2016, it became the default policy for the entire web by the end of 2023.
Mobile-first indexing is Google's policy of using the mobile version of a page — not the desktop version — as the basis for crawling, indexing, and ranking. After experiments starting in 2016, it became the default policy for the entire web by the end of 2023.
Why It Matters
In 2026, about 63% of global web traffic comes from mobile devices. Google decided rankings only make sense if pages are evaluated in the environment users actually experience — so the mobile version is treated as the "real" version. Content that's missing or broken on mobile effectively doesn't exist in Google's index, and anything that only appears on desktop contributes nothing to rankings.
How It Works
Google runs two crawlers:
- Googlebot Smartphone: Uses a smartphone user agent. The default crawler today.
- Googlebot Desktop: Used only in secondary cases.
With mobile-first indexing, Google builds its index based on what Googlebot Smartphone sees. Body content, meta tags, structured data, and internal links are all extracted from the mobile version.
Preparation Checklist
Responsive design: The recommended implementation. Same URL and same HTML for mobile and desktop eliminates content mismatch risk.
Content parity: Every piece of body text, image, video, internal link, and structured data that appears on desktop must also appear on mobile. "Mobile gets just a summary" is treated as content loss.
Meta tag parity: <title>, meta description, canonical, hreflang, and robots tags must all be present on the mobile version.
Image and video accessibility: Lazy loading should be scroll-triggered, and images/videos must use the same URLs and alt text on mobile.
Page speed: Mobile Core Web Vitals (LCP, INP, CLS) directly affect rankings.
Tap targets: Buttons and links must have enough spacing, and text should use readable font sizes (16px minimum).
If You Use a Separate Mobile URL (m.example.com)
If you still run a separate mobile domain or subdomain, you must configure:
<link rel="alternate" media="..." href="...">on the desktop page<link rel="canonical">on the mobile page pointing to the desktop version- Identical structured data on both versions
That said, Google strongly recommends responsive design — separate mobile URLs are costly to maintain long-term.
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