Google adds Gemini 3.5 Flash AI Mode and Search agents to Search

Google announced at I O 2026 that its AI Mode in Search has crossed the 1 billion‑monthly‑user mark and is being upgraded to the Gemini 3.5 Flash model, while also introducing AI Search agents that can monitor the web 24/7 for user‑specified criteria [2].

Gemini 3.5 Flash powers the next AI Mode

The upgrade replaces the previous Gemini model that underpinned AI Mode since its public rollout in 2025. Gemini 3.5 Flash promises faster response times and higher‑quality generation, though Google has not disclosed benchmark numbers. The change coincides with the expansion of AI Overviews—concise, AI‑generated summaries that now appear atop every search results page. Google says the new AI Search Box will also expand to accommodate longer natural‑language queries and allow users to attach images, videos, files, or Chrome tabs for richer context [2].

AI Search agents and the publisher backlash

Google’s AI Search agents let users supply a set of criteria—such as apartment size, budget, or product specs—and have the agent continuously scan news sites, blogs, and social platforms for matching content. The agents will be rolled out to Google AI Pro and Ultra subscribers in the summer, with broader availability slated for all users later in the year [2]. The move follows criticism that AI Overviews have eroded referral traffic for publishers. An analysis by Seer Interactive reported a 61 % drop in organic click‑through rates when AI Overviews were present, a trend Google disputes [3]. Adding to the tension, the UK Competition and Markets Authority (CMA) has ordered Google to display clearer attribution links in AI‑generated results and to let publishers opt out of AI features without penalty, giving publishers a new lever in negotiations [4].

What to watch

• Summer rollout of AI Search agents for Pro/Ultra subscribers, followed by a wider release later in 2026.
• CMA compliance timeline: Google must implement clearer attribution and opt‑out tools within nine months, with interim reporting expected before the deadline.
• User adoption trends: Whether AI Mode’s monthly user base continues to double each quarter, as Google claims, will signal the durability of the conversational search model.

Google’s push to embed generative AI deeper into Search—through faster models, richer query inputs, and autonomous agents—marks a decisive shift from traditional keyword search toward a more interactive experience. The regulatory response in the UK highlights the growing tension between AI‑driven convenience and publisher rights, leaving the balance of power in the search ecosystem still in flux.