---
title: "Mobile-first indexing, from 2016 test to 2023 completion"
url: https://seomadman.com/reports/mobile-first-indexing-completion-status
section: reports
published: 2026-07-06T00:00:00.000Z
modified: 2026-07-06T00:00:00.000Z
author: Adam Hafez
topics: ["Technical SEO", "Indexing"]
---

# Mobile-first indexing, from 2016 test to 2023 completion

## The short answer

Google tested mobile-first indexing from November 2016 and announced the rollout complete on 31 October 2023. Its current documentation says most Googlebot crawl requests now use the smartphone crawler, and warns that a mobile page with less content than its desktop equivalent loses that content from the index entirely.

## Key takeaways

- Google first announced it was testing mobile-first indexing on 4 November 2016, on the Google Webmaster Central Blog.
- The site-by-site rollout ran publicly from March 2018 through repeated deadline extensions in 2019 and 2020.
- Google announced the transition was complete on 31 October 2023, in a post titled "Mobile-first indexing has landed".
- Google's current Googlebot documentation states the majority of crawl requests now use the smartphone crawler, and a minority use the desktop crawler.
- Google warns that a mobile page with less content than its desktop equivalent has that content excluded from indexing, not merely deprioritized.

Mobile-first indexing is not a 2026 story so much as a finished one: Google announced the switch
essentially complete in October 2023, nearly seven years after the first public test. What is
current in 2026 is Google's own documentation describing what that switch means day to day, and
the parity failure mode it still warns sites about.

## The rollout, in Google's own dated posts

Google first announced it was testing mobile-first indexing on 4 November 2016, on the Search
Central (then Webmaster Central) blog. The idea: since most searches happen on mobile devices and
most sites still built desktop-first, Google would start basing indexing on the mobile version of
a page's content rather than the desktop version, for the sites it selected for the experiment.

The public, site-by-site rollout followed in "Rolling out mobile-first indexing," published in
March 2018, and continued through further posts in May 2019 (mobile-first indexing set as the
default for newly created domains) and March 2020 ("Announcing mobile first indexing for the
whole web"). Google extended its own deadlines more than once as sites it had flagged were not yet
ready; a July 2020 post and a November 2021 update both describe the same pattern of pushing the
remaining sites over individually rather than on a single fixed date.

Google declared the transition complete on 31 October 2023, in a post titled "Mobile-first
indexing has landed." Google did not publish a completion percentage. The post instead describes a
small remaining category of sites - those broken on mobile devices, blocking the mobile crawler
via robots.txt, or redirecting all mobile traffic to a homepage - that Google would keep crawling
with the legacy desktop Googlebot indefinitely, because there is no usable mobile version to index.
Search Engine Land's coverage of the same announcement quotes the post's framing directly: the
"trek to Mobile First Indexing is now complete."

## What it means in practice, and the common failure mode

Google's current mobile-first indexing documentation states the mechanism plainly: Google crawls,
indexes and ranks using the mobile version of a page's content, fetched with the smartphone
crawler. Its Googlebot documentation adds the crawl-side consequence of that: for most sites, the
majority of Googlebot crawl requests now use the smartphone crawler, with a minority still using
the desktop crawler for the exceptions described above.

The parity requirement is the part that produces real ranking losses. Google's documentation is
explicit that structured data must match between mobile and desktop versions of a page, that title
elements and meta descriptions must be equivalent across both, and - most consequentially - that
"if your mobile site has less content than your desktop site" the fix is updating the mobile
version so its primary content is equivalent to desktop's. Content that exists only on the desktop
version of a page is not indexed at a discount; under mobile-first indexing it is not indexed at
all, because Google never sees it. Sites that once built a stripped-down "mobile view" as a
performance shortcut, or that still hide secondary content behind a mobile accordion that never
loads in the DOM, are describing exactly the failure mode this documentation names.

## Why we care

Mobile-first indexing is not a project with an open action item for most sites anymore; Google
finished the rollout in 2023 and now treats it as the default mechanism, not a migration in
progress. The item worth auditing in 2026 is narrower and easy to miss: pull up your own mobile
rendering with Search Console's URL Inspection tool and compare it, section by section, against
desktop. Any text, image, or structured-data block present on desktop and absent on mobile is
invisible to Google, not merely deprioritized - and that gap is the one Google's own documentation
still calls out by name.

## Frequently asked questions

### When did Google finish moving all sites to mobile-first indexing?

Google announced completion on 31 October 2023, in a Search Central blog post titled 'Mobile-first indexing has landed.' Google did not publish a completion percentage; it described a small remaining set of sites - ones broken on mobile, blocking mobile crawling, or redirecting mobile visitors to a homepage - as staying on desktop crawling indefinitely.

### Does Google still use Googlebot Desktop at all?

Yes, for a minority of requests. Google's Googlebot documentation states the majority of crawl requests now use the smartphone crawler and a minority use the desktop crawler, without giving an exact split.

## Sources

1. [Mobile-first indexing](https://developers.google.com/search/blog/2016/11/mobile-first-indexing) - Google Search Central Blog (primary)
2. [Rolling out mobile-first indexing](https://developers.google.com/search/blog/2018/03/rolling-out-mobile-first-indexing) - Google Search Central Blog (primary)
3. [Mobile-First Indexing by default for new domains](https://developers.google.com/search/blog/2019/05/mobile-first-indexing-by-default-for) - Google Search Central Blog (primary)
4. [Announcing mobile first indexing for the whole web](https://developers.google.com/search/blog/2020/03/announcing-mobile-first-indexing-for) - Google Search Central Blog (primary)
5. [Mobile-first indexing has landed - thanks for all your support](https://developers.google.com/search/blog/2023/10/mobile-first-is-here) - Google Search Central Blog (primary)
6. [Mobile-first indexing best practices](https://developers.google.com/search/docs/crawling-indexing/mobile/mobile-sites-mobile-first-indexing) - Google Search Central (primary)
7. [What Is Googlebot](https://developers.google.com/search/docs/crawling-indexing/googlebot) - Google Search Central (primary)
8. [Google says mobile-first indexing is complete after almost 7 years](https://searchengineland.com/google-says-mobile-first-indexing-is-complete-after-almost-7-years-434011) - Search Engine Land