What is mobile-first indexing?

Mobile-first indexing means that Google bases indexing and ranking of a page on the version of the page shown to its smartphone crawler.

The transition took years and was completed in 2024. According to Google’s announcement of June 3, 2024, after July 5, 2024, the remaining sites have also been crawled with the smartphone crawler only (Googlebot Smartphone), and content that cannot be accessed on a phone at all can no longer be indexed. In other words, for Google the real state of a site is its state on a phone.

What happens to content that is on the desktop but not on the phone?

For Google, it does not exist. A product table hidden on a phone, a link to a certificate page found only in the desktop menu, or a section that does not load on a phone does not enter the index, even if it is on the site. If a separate mobile version (an address starting with m.), common on old sites, carries less content than the desktop version, it is that incomplete content that is indexed.

What should be checked on a manufacturer’s site?

Do product tables and technical data also open on a phone, or are they hidden?
Are the certificate record and the certificates' PDFs accessible from a phone?
Are all the links in the menu also in the phone menu?
Does the page on the phone carry the same headings and text as on the desktop?
Is the structured data also present in the phone version?

The easiest way to check is to look at the page as Google sees it with URL inspection in Search Console and compare it with how it looks when you open it on a phone. If there is a difference, the problem is not in the design but in the structure: content should stay in place on the phone, only its arrangement should change. A table that needs horizontal scrolling on a phone is also a warning sign: the content is there but hard to read.

Mobile-first does not mean “the phone version is more important”; it means Google reads a page through a phone’s eyes. On a responsive site, where the same address sends the same HTML to every device, the content is the same on both devices; the problem usually arises on separate mobile sites and in layouts that hide content on a phone.

There is a similar limit for AI crawlers: most major AI crawlers do not run JavaScript. A product table that loads later on a phone only through JavaScript is therefore a risk for two readers at once: delayed for Google’s smartphone crawler, absent altogether for AI crawlers.

How this change affects the visibility of a site that is not updated is covered in the cost of an outdated website guide; the reason for the speed gap on phones is in the mobile performance gap guide.

For a site that shows your certificates as a record buyers can verify, B2B website builds and measures the certificate page, the product scope and the path to a quote together.

Certified manufacturing

noindex is a directive asking that a page not be added to a search engine’s index, given either with the robots meta tag inside the page or with the server’s X-Robots-Tag response header. Being found on Google

Redirect chain A redirect chain is when an address reaches its final address not in a single hop but by passing through more than one redirect; for example, if an old address is redirected first to an intermediate address and from there to the final address, there is a two-hop chain. Site migration

Reflow A reflow is the browser recomputing the positions and sizes of elements on a page after a change. Performance

Relative luminance is the value expressing a colour’s perceived lightness between 0 and 1, and it is the basis of the contrast ratio calculation. Accessibility

Screen reader A screen reader is assistive technology that turns on-screen content into speech or braille output and lets the user navigate by keyboard. Accessibility

Search Console is a free service from Google for monitoring a site’s status in Google Search and for seeing and fixing its problems. Being found on Google

Semantic HTML means choosing each element for its meaning rather than its appearance — a heading element for a heading, a button element for a button, a list element for a list. Accessibility

Sitemap A sitemap is a file, usually written in XML, that lists the addresses of a site’s pages and, optionally, their last modification dates for search engines in a single file. Being found on Google

Social compliance audit A social compliance audit is the examination by an independent auditor of working conditions, occupational health and safety and business ethics at a production site against a code of conduct. Certified manufacturing

Soft 404 A soft 404 is a page that shows visitors “page not found” or empty content but returns a 200 (success) code from the server instead of an error code; Google treats these pages as error pages and does not index them. Site migration

Structured data is an additional layer that labels a page’s content with a standard vocabulary machines can understand. Answer engines

Text expansion is the same content being of different lengths in different languages, and the layout having to flex accordingly. Multilingual

TLS certificate lifetime is the period from the day the certificate that provides a site’s HTTPS connection is issued to the day its validity ends. Certified manufacturing

Total cost of ownership is the sum of all the costs of buying an asset or service and using it over its service life. Certified manufacturing

Transaction certificate A transaction certificate is the document, issued by a certification body under Textile Exchange standards, that shows a specific delivered consignment of goods is certified. Certified manufacturing

Translation memory A translation memory is a database that stores previously translated sentences and suggests them when the same or a similar sentence comes up again. Multilingual

TTFB (Time to First Byte) is the time between the browser sending a request and receiving the first byte from the server. Performance

URL inventory A URL inventory is a single list that gathers every address of a site that search engines know — current pages, address variants and old addresses; in a site redesign or migration, the redirect map is derived from this list. Site migration

WCAG (Web Content Accessibility Guidelines) is the international standard published by the W3C that defines the accessibility of web content through testable success criteria. Accessibility

x-default is a special hreflang value declaring the default page to show when no language version matches the user’s language. Multilingual

What happens to content that is on the desktop but not on the phone?

What should be checked on a manufacturer’s site?

SOURCES