Mobile-First Indexing: What It Means and How to Check Your Site
Mobile-first indexing means Google mainly uses the mobile version of your pages to index and rank them. If your phone version is missing content that your desktop version has, Google may never see it. This guide explains what changes, how to check your site and what to fix.
- Plain definition
- Four-step check
- Match checklist
- Responsive design
| Item | Must match on mobile? |
|---|---|
| Main content | Yes |
| Titles and meta descriptions | Yes |
| Structured data | Yes |
| Images and alt text | Yes |
| Robots meta tags | Yes |
What mobile-first indexing is
Mobile-first indexing means Google predominantly uses the mobile version of a website’s content for indexing and ranking. Google crawls your pages with a smartphone crawler and stores what that crawler sees.
This is because most people search on phones. Google’s documentation explains the change and says sites should serve the same content on mobile and desktop. Google has also stated that sites that cannot be accessed by mobile devices are no longer indexed.
It is not a separate ranking boost for mobile sites. It is about which version Google reads. A desktop-only experience gives Google less to work with.
- Google reads your phone version first
- Anything missing on mobile may be ignored
- Responsive design avoids most problems
- The fix is matching, not rebuilding
How a site can serve mobile users
Responsive design
One URL and one set of code that adapts to screen size. Google recommends this because it is the simplest to keep consistent.
Dynamic serving
One URL, but the server sends different HTML depending on the device. The two versions must carry equivalent content.
Separate mobile URLs
An m. subdomain or similar. It needs the most care, with matching content, annotations and redirects. Most sites avoid it.
How to check your site
Open your site on a real phone
Scroll through your main pages. Look for text that is cut off, buttons too small to tap, or sections that are missing compared with desktop.
Use URL Inspection in Search Console
Paste a page into the URL Inspection tool and view the crawled page. Search Console shows the page as Google’s crawler fetched it. See Search Console setup.
Compare mobile and desktop
Open the same page on both. Check headings, body text, images, links and any structured data. Anything on desktop that is hidden or absent on mobile is a risk.
Run Lighthouse or PageSpeed Insights
Test the page on mobile for speed and usability. Google’s separate Mobile-Friendly Test tool has been retired, so use Lighthouse in Chrome DevTools or PageSpeed Insights instead.
What must match on mobile
Content and markup
- Same main text on mobile and desktop
- Same headings and page titles
- Same meta descriptions
- Same structured data
- Same robots meta tags
Media and resources
- Images with alt text and supported formats
- Videos that can be found and played on mobile
- CSS, JavaScript and images not blocked in robots.txt
- Lazy-loaded content that loads when it enters view
Hidden tabs and accordions are fine for users as long as the content is in the page. Google has said content in expandable sections on mobile is treated normally.
What to do on WordPress
Pick a responsive theme
Most modern themes, including Astra, adapt to screen size. Avoid separate mobile plugins that serve different content.
Be careful with plugins
Pop-ups, sliders and page builders can hide content or cover the page on phones. Test after adding them. See best WordPress SEO plugins.
Mobile-first mistakes to avoid
Less content on mobile
Trimming text for small screens means Google indexes the trimmed version.
Blocking resources
Blocked CSS or JavaScript stops Google rendering the page properly.
Tiny tap targets
Buttons and links too close together frustrate visitors.
Intrusive pop-ups
Full-screen overlays make pages hard to use on phones.
Only testing on desktop
Problems stay invisible.
Mobile-first indexing questions
Is my desktop site ignored?
Not ignored, but the mobile version is the one Google mainly uses for indexing and ranking.
Do I need a separate mobile site?
No. Responsive design is simpler and is what Google recommends.
Does mobile-first indexing change my rankings?
Only if your mobile version differs from desktop in ways that lose content or signals. If they match, there is little to worry about.
What about a desktop-only site?
Google crawls with a smartphone crawler, so a site that cannot be used on mobile is at risk of not being indexed properly.
Where do I see mobile problems in Search Console?
Use URL Inspection for single pages and the Core Web Vitals and page experience reports for site-wide patterns.
Platform advice for WordPress is practical guidance, not a Google requirement. No ranking is guaranteed.