Google rolls out Gemini 4 Hydrogen in Search amid core update

Gemini 4 Hydrogen arrives in Search

Google has deployed what it calls its largest model upgrade to Google Search to date, known as Gemini 4 Hydrogen. According to Search Engine Roundtable, Google executives Nick Fox and Robby Stein described the change as a major step up for the search engine.

The company lists several improvements: faster responses, better understanding of queries, improved query fan-out and linking, more visual results and richer language handling. Query fan-out is the process where Google breaks a question into several sub-questions to answer it more fully.

The rollout lands only days after the previous Gemini 4 Carbon release, and while the November 2026 core update is still being distributed. That timing has drawn attention in search forums because ranking shifts from the core update and the model change may be hard to tell apart.

Search Console reporting bug confirmed

Google has acknowledged a logging fault in the Generative AI performance report within Search Console. The company says impressions were undercounted between 9 and 11 November 2026.

Search Console is Google's dashboard for site owners to track how their pages perform in search results. The affected report covers traffic from AI-powered search features.

Site owners who saw a dip in impressions during those three days may therefore not need to look for a cause on their side. Google has not said whether the missing data will be restored.

AI images return to AI Overviews

Google appears to be switching the ability to generate images directly within AI Overviews back on for some users. AI Overviews are the short AI-written summaries that appear above normal results for some queries.

The feature was first announced in July 2026 and paused the following month after criticism. Search Engine Roundtable reports it is now reappearing for some searchers, though Google has not published a formal statement on the return.

Separately, Google's John Mueller noted on Bluesky that merchant images created with AI must carry metadata marking them as AI generated.

New guidance and advertiser changes

It explains how site owners can spot visits from Google Search by checking the HTTP Referer header, the field a browser sends to show where a click came from.

Google Ads also revised its Conversion Lift documentation, adding more detailed technical requirements and troubleshooting steps for advertisers running incrementality studies, which measure whether ads truly cause extra sales.

Merchant Centre and publisher licensing news

Google has tightened the editorial rules for Merchant Centre promotion titles, banning dates in any format in the redemption section of a listing. The company has also removed the experimental label from the Deal Ends annotation on Product Listing Ads, and says that feature is no longer available in India.

A new section named Highlighted on the web has appeared in the mobile version of Google Shopping, according to Search Engine Roundtable's editor, who could not see it on desktop.

Elsewhere, the Internet Licensing Collective, a nonprofit body led by publishers, has launched with Yahoo Scout as its first commercial partner. Yahoo Scout will pay publishers through the collective when their content is used in AI answers.