NotebookLM gets ‘significantly improved’ chat: Saved history, 1M token context window

Abner Li | Oct 29 2025 - 10:43 am PT

The chat feature in NotebookLM is getting significant improvements today to “performance, quality, and contextual understanding,” as well as the ability to set goals.

NotebookLM chat is now “powered by the latest Gemini models,” though Google doesn’t explicitly specify if it’s Gemini 2.5. This is then paired with Gemini’s “full 1 million token context window” for “all plans,” which presumably includes free users. This is 8x larger than before, and you’ll see the difference with large documents collections. This is rolling out starting today.

Google has also increased NotebookLM’s memory or “capacity for multiturn conversation” by over 6x to make possible longer conversations.

Meanwhile, NotebookLM will now explore sources from multiple angles to go “beyond your initial prompt to synthesize findings into a single, more nuanced response.”

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This is especially important for very large notebooks, where careful context engineering is critical in delivering a high quality and trustworthy answer, grounded on the most relevant information in your sources.

A big quality-of-life improvement rolling out over the next week sees NotebookLM automatically save your conversation history, with the option to delete. As such, you can continue a session after closing the app. In shared notebooks, the chat is only visible to you.

Google notes a “50% improvement in user satisfaction with responses that use larger amounts of sources.”

Meanwhile, NotebookLM now lets you set a conversational goal, voice, or role for the chat. For example:

Treat me like a PhD candidate: You are my research advisor. Rigorously challenge every assumption. Ask probing questions, identify logical fallacies and force me to defend my work from the ground up.
Act as a lead marketing strategist: Your response must be an immediate action plan. Be analytical and direct, and focus exclusively on the concrete strategies and critical-path steps needed to achieve the goal fast.
Analyze the provided material from three distinct perspectives: As a strict academic focusing on evidence and logical consistency, as a creative strategist looking for non-obvious connections and innovative applications, and as a skeptical reviewer actively searching for gaps, flaws and potential problems in the conclusions.
Act as a Game Master for a text-based simulation. Present a high-stakes scenario with a specific goal and a step limit (e.g., 10). I make all the choices. Narrate the outcomes vividly, using realistic, scenario-relevant details.