What happened in SEO & AI search news this month?

Each month, Lumar’s in-house tech SEO experts hand-pick some of the SEO industry’s top news stories from across the web to keep you up-to-date on all things SEO and website optimization.

For our May 2026 SEO & GEO/AEO news roundup, the top headlines include:  

• Google I/O 2026 brought the biggest Search overhaul in 25 years — Plus: AI Mode has surpassed one billion monthly users just one year after launch, with query volume hitting an all-time high last quarter.
• Google published its first official AI search optimization guide covering crawlability, content structure, and technical SEO foundations for AI Mode and AI Overviews.
• Google’s May 2026 core update began rolling out on May 21st — it’s the second core update of the year, running in parallel with ongoing AI feature expansion in Search.
• Google launched a cross-channel shopping cart experience across Search, Gemini, and YouTube — letting users save and manage products across platforms as part of a more agentic shopping journey.
• Google Analytics added a new AI assistant traffic channel in GA4 — automatically grouping visits from tools like ChatGPT, Gemini, and Claude under a dedicated ai-assistant medium.
• AI search is more likely to cite in-depth content — that’s according to Google’s Nick Fox at Google Marketing Live 2026.
• Google removed the last remaining FAQ rich results from Search — including the phasing out of FAQ reporting in Search Console, marking another step away from traditional rich result features.
• Snap and Perplexity ended their planned $400 million AI search integration deal — a reminder that AI search distribution partnerships inside major consumer platforms are far from guaranteed.
• OpenAI made GPT-5.5 Instant ChatGPT’s new default model — with improvements in factuality, image understanding, and the model’s ability to decide when to use web search to inform its generative responses.
• (and more, below!)

Dive into the details behind the SEO and GEO/AEO headlines this month below…

May 2026 SEO & GEO/AEO News Roundup:

Google I/O 2026: Google unveils biggest Search overhaul in 25 years as AI Mode hits 1 billion monthly users 

The hotly anticipated Google I/O 2026 summit saw Google unveil what it calls the biggest transformation in Search for more than 25 years. Updates include a redesigned AI-first search experience that adds more AI features than ever before, from persistent conversational context to autonomous “information agents” designed to help complete tasks.

At the I/O event, Google announced that, just one year after its debut, AI Mode has surpassed one billion monthly users, with queries more than doubling every quarter since launch. Google also reported that query volume reached an all-time high last quarter — framing AI Mode not as a replacement for Search but as a driver of more searching, not less.

The Google Search updates announced at I/O 2026 stop short of making AI Mode the default for Google Search, but it does reinforce how far we’ve moved away from traditional link-based SERPs. Search is becoming increasingly reliant on these task-oriented AI experiences, the likes of which promise to make tracking and monitoring SEO performance a whole lot more complicated.

(Source: Google’s The Keyword Blog ; Google I/O Keynote Videos)

---

Google publishes AI search optimization guide

Google has published its first formal documentation on optimizing for AI, “Optimizing your website for generative AI features on Google Search.” The focus is naturally on Google-owned features such as AI Mode and AI Overviews; however, in theory much of it should be transferable to other AI systems.

Much like traditional search, the emphasis is put on creating helpful, structured, and easily accessible content. The document also highlights the importance of page clarity and crawlability, with strong technical SEO foundations continuing to prove significant.

(Source: Google Developers Blog)

---

Google introduces cross-channel “universal” shopping carts

Google has announced a new shopping cart experience that works across platforms such as Search, Gemini and YouTube. For the first time, users can save, track, and manage products in one place while navigating across different apps and products.

The feature is designed to support more agentic shopping journeys, with AI surfacing price changes, availability updates, and product recommendations. It reinforces Google’s shift towards an ongoing AI-assisted shopping experience, rather than a series of isolated searches.

Per Google’s Universal Cart announcement:

“Universal Cart is an intelligent shopping cart and your new hub for shopping on Google. It works across merchants and across services, so you can add things to your cart while you’re browsing Search, chatting with Gemini, watching YouTube or even reading your Gmail.”

“The moment you add a product to your cart, it gets to work in the background — finding deals and price drops, giving you insights on price history and alerting you when an item is back in stock. It all runs on our Gemini models, so your cart gets even smarter as the models improve.”

(Source: Google’s The Keyword Blog)

---

Google releases data on how people are using AI Mode

A year on from the full launch of AI Mode in the US, Google has published data on its usage. The report shows that users are increasingly treating AI Mode differently to traditional search, leaning heavily on its ability to process complex, multi-layered queries.

Searches in AI Mode tend to be more exploratory in nature, with users asking follow-up questions and sometimes engaging in lengthy conversations with the bot. For site owners, it’s less about ranking for specific queries and more about ensuring your brand is visible in AI-driven systems.

Per the Google publication, “How people are using AI Mode in the US”: 

“AI Mode isn’t just changing how people search — it’s expanding the very definition of what’s searchable.”

(Source: Google)

---

Google launches its May 2026 core update

Google officially announced the rollout of the May 2026 core update on May 21, 2026. Google described it as “a regular update designed to better surface relevant, satisfying content for searchers from all types of sites,” and the rollout is expected to take approximately two weeks to complete. The update is global, affecting all regions and languages.

The May core update is Google’s second of 2026. As usual, no specific focus has been publicly stated for this core update, but its timing is interesting given the ongoing volatility caused by the expansion of AI features in Search. Both occurring in parallel will make it harder to separate algorithmic ranking shifts from broader AI-driven traffic changes.

(Source: Search Engine Journal)

---

Google Analytics adds new AI assistant traffic channel

Google has introduced a new AI assistant traffic category in GA4 that automatically groups visits coming from recognized AI tools such as ChatGPT, Gemini, and Claude.

The update assigns a new ai-assistant medium, putting this traffic into a dedicated default channel group. The goal is to make it easier for site owners to identify and compare AI-driven visits against traditional sources like organic search and direct traffic.

(Source: SEO Roundtable)

---

Google drops remaining FAQ rich results from Search

Google has removed any remaining FAQ rich results from appearing in Search. The feature has already been heavily restricted for most websites since 2023. The change also includes the phasing out of FAQ reporting in Search Console, with additional tooling support expected to be removed later in the year. 

FAQ structured data remains valid, but no longer produces visible SERP enhancements. The news marks another step in Google’s gradual reduction of traditional rich result features in favor of AI-driven experiences.

(Source: Search Engine Land)

---

AI search rewards content that goes deeper, says Google’s Nick Fox at Google Marketing Live 2026

In a Semafor interview about the future of AI search mechanics at this month’s 2026 Google Marketing Live event, Google’s Nick Fox (SVP of Knowledge & Information) emphasized that the proliferation of generative AI summaries heightens the algorithmic premium on “deep content.” Fox noted that while AI answers handle simple informational queries efficiently, they can’t replace rich, original human perspectives. As user behavior trends toward longer, more conversational queries, the AI systems seeks out primary evidence from external sources.

Fox’s advice for GEO/AEO? In the interview (around the 15-minute mark), he says:

“The biggest piece of advice we give is that the way to optimize for AI search is the same way to optimize for search: create great content that, as users, you would want. The additional piece of advice we give is: go beyond the surface level.”

“If you assume that the AI will provide sort of a first-level response or high-level framing, the content that will do the best within AI is one that goes one level deeper [or] two levels deeper and is really helpful.”

   
For content marketers and SEO pros, the takeaway is clear: Google continues to actively optimize its ranking systems to prioritize unique information that AI models cannot easily replicate. Content that relies on generic synthesis faces declining visibility, while firsthand data, unique brand perspectives, and expert analysis form the foundation for visibility in the AI era.

Watch the interview from Google Marketing Live 2026 here:

(Sources: Semafor ;  Search Engine Land ; Google Marketing Live 2026 interview video)

---

Snap ends its planned $400M Perplexity AI search deal

TechCrunch reported earlier this month that Snap and Perplexity “amicably ended” a previously announced $400 million deal that would have integrated Perplexity’s AI search engine into Snapchat. The partnership had been positioned as a way to bring conversational answers directly into Snapchat’s chat interface, but Snap said the companies had not agreed on a path to broader rollout.

For AI search watchers, the reversal is a useful reminder that distribution deals will be a major battleground — but not every AI search partnership will stick. Perplexity’s answer-engine model remains highly relevant to GEO/AEO, yet this update shows that embedding AI search into large consumer platforms can be commercially and operationally complicated. For brands, the broader lesson is to track not only standalone AI search products, but also where those products gain or lose distribution inside social, browser, and app ecosystems.

(Source: TechCrunch)

---

OpenAI releases GPT-5.5 Instant as ChatGPT’s new default model

This month, OpenAI announced that GPT-5.5 Instant will now be ChatGPT’s new default model, saying it is designed to provide smarter, clearer, more accurate, and more personalized responses. OpenAI also highlighted improvements in factuality, image understanding, STEM questions, and the model’s ability to decide when to use web search.

Per the OpenAI announcement:

“GPT‑5.5 Instant is a generally smarter model that’s more capable across everyday tasks, including improvements in analyzing photo and image uploads, answering STEM-related questions, and deciding when to use web search to provide a more useful answer.”

For GEO and AI search practitioners, the “when to search the web” piece is particularly important. As ChatGPT becomes better at deciding when fresh external information is needed, the relationship between model behavior, source retrieval, and content citation becomes more strategically important. Brands that want to be discovered in ChatGPT environments need to consider whether their content is accessible, authoritative, up to date, and useful enough to be retrieved when the model determines that web grounding is needed.

(Source: OpenAI announcement)

---