NotebookLM upgraded to Gemini 3.5 with Antigravity and a secure cloud computer

Google's research assistant NotebookLM received a substantial upgrade on June 8, moving its chat onto Gemini 3.5 and integrating Antigravity, Google's agentic coding platform. The combination improves answer accuracy and gives users clearer visibility into the model's reasoning steps.

The marquee addition is a per-notebook secure cloud computer that allows NotebookLM to write and execute code as part of research tasks — turning it from a passive summarizer into an active analyst that can run computations, parse data, and produce richer outputs. Google also added new output formats and, notably, the ability to expand search beyond a user's uploaded sources to find new material. Google product lead Josh Woodward, amplified by CEO Sundar Pichai on X, called the cross-source expansion 'the new killer NotebookLM feature.'

The update slots into Google's broader 2026 push to turn Gemini into a comprehensive work system spanning research, reasoning, voice, video and Android, via features like Deep Think and Deep Research. It also lands the same week Google's Gemini surfaced as the engine behind Apple's new Siri AI — a strong week for Gemini's external footprint.

Competitively, the secure-cloud-computer concept directly parallels OpenAI's Codex-centric agent push and Anthropic's AgentCore sandboxes: each vendor is racing to let its assistant safely run code on the user's behalf. The differentiation will hinge on accuracy and grounding quality. Skeptics will watch for hallucination in code execution and whether the expanded-source search dilutes NotebookLM's original appeal as a tool grounded strictly in user documents. Reaction in r/GoogleGemini and from Google AI Studio lead Logan Kilpatrick ('bullish on Gemini') was upbeat.