Google's September 2026 Spam Update, Auto-Expanding AI Overviews and the AI Contribution Pilot: What Publishers Should Do Now

TL;DR: Google started rolling out its fourth spam update of 2026 on 24 September, a month after it began expanding AI Overviews into full AI Mode answers by default for some queries, and a week after reports that it is paying a pilot group of small and mid-sized publishers when their content "contributes significantly" to AI answers. Each change pulls in a different direction. This guide covers what is confirmed, what is not, and the concrete checks worth doing this week.

Google's Search team has had a busy month, and most of it lands on publishers. Below are the three developments that matter, in order of urgency, followed by a checklist.

1. The September 2026 spam update is rolling out now

Google began the September 2026 spam update on 24 September 2026 at 9:15 a.m. Pacific time, and says the rollout may take up to two weeks. Search Engine Journal's report notes this is the fourth spam update of the year, after March, June and August, and that Google offered no detail about what it targets beyond confirming that it "applies globally and to all languages."

Google's standing advice for sites that see ranking changes is to review its spam policies, and the company repeated its usual caveat: making changes "may help a site improve if its automated systems learn over a period of months that the site complies with its spam policies." In other words, a recovery is measured in months, not days.

Two spam-policy additions from earlier in 2026 are worth knowing about because they are new enough that many sites have not audited for them:

• Back-button hijacking. Pages that defeat the browser's Back button with history.pushState or replaceState tricks, including scripts injected by third-party ad or affiliate platforms, were added to the spam policies in April, with enforcement live since June. If you run third-party scripts, test the Back button on a real phone.
• Site reputation and scaled content abuse continue to be the policies most often cited in manual actions. Programmatic pages that exist only to rank, and syndicated or sponsored sections that ride on a host site's reputation, remain targets.

If your traffic moves during the rollout window, resist changing anything structural until the update has finished. Annotate the dates in your analytics, compare against Google's confirmed update list, and only then decide whether the drop correlates with this update or with something else.

2. AI Overviews now expand into AI Mode answers automatically

On 28 August 2026, Search Engine Roundtable documented that Google had begun expanding AI Overviews into full AI Mode responses by default for certain queries. Instead of a short summary with a "Show more" control, the page loads the complete AI Mode answer and an "Ask anything" follow-up box immediately, which pushes the organic results further down.

Google's statement: "For some queries, AI Overviews may dynamically expand for topics where our systems determine it's most useful for people. Our research has shown that with this dynamic experience, users find Search more helpful and engage deeper in follow-up exploration." Google has not said which query types trigger the expansion. One safeguard was described: if a user has already started scrolling below the overview, the automatic expansion stops so their position on the page is preserved.

For publishers this raises the stakes on being cited inside the answer rather than ranking beneath it. A few points from Google's own documentation are useful here:

• Google's AI features documentation says there is no AI-specific opt-out file. Since 31 August 2026 every site has a "Search generative AI" control in Search Console (include, exclude or inherit) that governs eligibility for AI Overviews and AI Mode. It is not a ranking signal.
• Since 18 September 2026, Google's preferred sources documentation states that a site must be included in that generative-AI control to appear as a user's preferred source in AI Mode and AI Overviews. If you have opted out, you have also opted out of the badge.
• Google's AI optimization guide is explicit that llms.txt and similar AI text files are not needed for Google Search and do not affect visibility. The same guide says content does not need to be "chunked" for AI. What does matter is the same thing that always did: content that answers the question directly, with clear headings, dates, an identifiable author and primary sources.

3. The AI contribution pilot: Google is paying some publishers

Reported by Digiday and summarised by 9to5Google on 17 September, Google is testing a programme in which publishers "accumulate earnings when your content contributes significantly to AI-generated responses in participating products." Participating sites see a payout panel inside Google Search Console.

What is known: the pilot involves at least dozens of publishers, is focused on small and mid-sized sites rather than only large news organisations, and extends beyond news. Google's stated aim is to "partner with websites whose content meaningfully contributes to the freshness and factuality of generative AI responses." The programme was publicly teased in June and follows a separate commercial partnership programme with major news publishers announced in late 2025.

What is not known: payment rates, how "contributes significantly" is measured, whether or when the pilot opens to applications, and how long it will run. Participants told Digiday the information they received was basic. Treat this as a signal about where Google wants to go, not as a revenue line you can plan on.

What to do this week

1. Do not touch structure during the spam rollout. Record the 24 September start date, wait for Google to confirm completion, then compare. If you are hit, review the spam policies before changing anything.
2. Test the Back button on your top ten pages on a phone, with ads and consent scripts loaded. If it takes two taps to leave, find the script responsible.
3. Check the "Search generative AI" control in Search Console. Make sure it is set deliberately, and understand that "exclude" also removes preferred-source eligibility.
4. Make citation easy. For each page that matters, put a direct answer in the first paragraph, use question-shaped headings, show a publication and updated date, name the author, and link to primary sources. This is what Google's own guide asks for, and it is also what our earlier analysis of AI Overviews in 2025–2026 found separates cited pages from ignored ones.
5. Serve your content without JavaScript. Googlebot renders pages, but the AI search crawlers from OpenAI (OAI-SearchBot), Perplexity (PerplexityBot) and Anthropic (Claude-SearchBot) mostly do not. If your site is a single-page app, check what those crawlers receive with curl -A OAI-SearchBot https://yoursite.example/some-page and make sure the article text is in the response.
6. Keep Core Web Vitals honest. A slow page is still a slow page in AI Mode. Our INP guide covers the responsiveness metric that most sites still fail.

Sources

• Search Engine Journal, Google September 2026 spam update
• Google Search Status Dashboard, ranking updates history
• Search Engine Roundtable, Google AI Overviews expand into AI Mode responses
• 9to5Google, Google AI contribution pilot tests paying websites
• Google Search Central, AI features and your website, Preferred sources, AI optimization guide