# Mobile SEO: What to Watch for Under Mobile-First Indexing

Author: Fatih Emin Çakıroğlu (https://fatihemincakiroglu.com)
Source: https://fatihemincakiroglu.com/en/blog/mobil-seo
Published: 2026-10-20
Updated: 2026-10-20

Many teams still design and sign off a site on a desktop screen and then "squeeze" the mobile version in. Yet Google has long relied on the mobile version; every paragraph trimmed and every link removed on mobile is ignored in Google's eyes too.

This article covers the current state of mobile-first indexing, content parity between desktop and mobile, content inside accordions and tabs, how to test the mobile experience, and how Core Web Vitals fit in.

> Short answer: Google crawls and indexes the mobile version of sites with its smartphone crawler and uses it for ranking. The mobile page should carry the same main content, titles and descriptions, structured data and robots tags as desktop. Putting content in accordions or tabs is fine; removing it is the problem.

## Where mobile-first indexing stands today

Google's mobile site documentation is clear: Google uses the mobile content crawled with the smartphone agent. The transition took years; in October 2023 Google announced it had largely finished with a post titled "Mobile-first indexing has landed", and a final announcement in June 2024 covered the last group of sites.

According to Google's June 2024 announcement, after 5 July 2024 content that is not accessible on mobile devices at all can no longer be indexed. The practical conclusion is simple: as of October 2026, do not plan around a "we are not mobile-first yet" scenario; the mobile version is the version Google sees.

> **Is a mobile page mandatory?** According to Google's documentation, a separate mobile page is not required to be indexed, but a mobile-friendly experience is very strongly recommended. Responsive design, with one URL and one HTML, solves this with the least maintenance.

## How to achieve content parity between desktop and mobile

Google wants mobile content to be equivalent to desktop even when the design differs. I turned the areas listed in the documentation into a checklist table:

| Area | Google's expectation | Mistake I often see |
| --- | --- | --- |
| Main content | Equivalent to desktop | Shortened product descriptions on mobile |
| Title and meta description | Equivalent on both versions | A generic title in the mobile template |
| Robots meta tags | The same tags | A forgotten noindex on the mobile version |
| Structured data | The same markup (Breadcrumb, Product, VideoObject etc.) | Product schema missing from the mobile theme |
| Images | Same alt text, quality images, stable URLs | Low resolution and missing alt text on mobile |
| Internal links | Important links present on mobile too | Half the categories missing from the mobile menu |

The last row is not a separate item in the documentation, but it is one of the costliest mistakes in audits: category links dropped from the mobile menu also weaken Google's path to those pages. To find what is missing on mobile, apply the crawl method in the [technical SEO guide](https://fatihemincakiroglu.com/en/guides/teknik-seo) with a smartphone user agent.

## Are accordions, tabs and hidden content a problem?

Putting content in accordions or tabs to save space on mobile is common, and Google's documentation recommends this over deleting content. The key distinction is whether the content is in the HTML.

**Safe**
- Content in the HTML, collapsed in an accordion
- Tabs ready when the page loads
- Images loading as they enter the viewport
- The same text as desktop

**Risky**
- Content fetched from the server only on click
- Description loaded by a separate request after "See more"
- Main content triggered by scrolling or tapping
- Sections removed entirely on mobile

In Google's words, Googlebot will not swipe, click or type to see main content, so do not lazy-load primary content upon user interaction. I explain how to test content that arrives later through JavaScript in the [JavaScript SEO](https://fatihemincakiroglu.com/en/blog/javascript-seo) article.

## How to test mobile usability

The Mobile Usability report in Search Console and the Mobile-Friendly Test tool were retired in December 2023; Google points to Chrome's Lighthouse for evaluating the mobile experience. This is the test flow I use:

**Mobile test flow**
1. **URL Inspection**: In a live test, check the HTML and screenshot the smartphone crawler sees.
2. **Lighthouse**: Review performance, accessibility and best-practice warnings in mobile mode.
3. **A real device**: Try forms, the menu and checkout steps on a mid-range Android phone.
4. **Field data**: Track mobile URL groups separately in the Core Web Vitals report.

- Are tap targets too close together; are buttons easy to press with a finger?
- Is text readable without zooming; is there horizontal scrolling?
- Do pop-ups and cookie banners cover the main content?
- Is the phone number tappable, and does the address open in a maps app?

## How do Core Web Vitals affect mobile SEO?

Core Web Vitals thresholds are the same on mobile and desktop: LCP of 2.5 seconds, INP of 200 milliseconds and CLS of 0.1 or less count as "good". But because mobile devices and networks are slower, the same page often scores worse on mobile.

On mobile, LCP is most often hurt by large hero images and slow server response, INP by heavy third-party scripts, and CLS by images without dimensions and late-loading banners. For measurement and fixes, see [Core Web Vitals 2025](https://fatihemincakiroglu.com/en/blog/core-web-vitals-2025); speeding up heavy templates is part of my [performance and growth service](https://fatihemincakiroglu.com/en/performance-growth).

## Notes for sites with a separate mobile site (m.)

If you still run a separate-URL mobile site such as m.example.com, the rules are stricter. Google says the desktop URL is always the canonical and the mobile URL its alternate; hreflang should point mobile to mobile and desktop to desktop, and error status codes should match on both versions.

Because maintenance cost and error risk are high, I usually recommend moving a separate mobile site to responsive design; since that is a URL change, it should follow the redirect plan in the [site migration SEO guide](https://fatihemincakiroglu.com/en/guides/site-tasima-seo).

A large share of mobile searches carries local intent; for businesses such as clinics, law firms or shops, keeping the mobile page consistent with your [Google Business Profile](https://fatihemincakiroglu.com/en/blog/google-business-profile) also matters. For clinics I run this work within [healthcare SEO](https://fatihemincakiroglu.com/en/industries/healthcare-seo). If you want to see what is missing from your mobile version, I can take a look through [SEO consulting](https://fatihemincakiroglu.com/en/seo-consulting); let's set up a [short call](https://fatihemincakiroglu.com/en/book-a-call).

## Frequently Asked Questions

### Most of my traffic is desktop; is the mobile version still what counts?

Yes. Indexing and ranking use the version Google sees with its smartphone crawler; most of your visitors coming from desktop does not change that. Your desktop users also see results from the same index.

### How do I see which crawler Search Console uses for my site?

The URL Inspection tool shows which crawler fetched the page. The Crawl stats report under Settings also breaks requests down by Googlebot type.

### Is AMP required for mobile SEO?

No. AMP is not a requirement for mobile-first indexing. A fast, responsive standard page does the same job; if you remove an existing AMP version, redirect the AMP URLs to the standard pages.

### Is a full-screen pop-up on mobile a problem?

Pop-ups that cover the main content and are hard to close hurt user experience and conflict with Google's page experience approach. Keep legally required cookie and age-verification notices reasonably sized and easy to dismiss.

### Can I use different images on mobile and desktop?

You can, but Google notes that different image URLs may cause a temporary loss of image traffic during the transition. Where possible, serve the same image in responsive sizes and keep alt text identical on both versions.

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Please attribute as: "Fatih Emin Çakıroğlu (fatihemincakiroglu.com)". Original: https://fatihemincakiroglu.com/en/blog/mobil-seo