Gemini 3.1 Pro Preview

Gemini 3.1 Pro Preview sits inside Google's Gemini 3 family as the reasoning-focused tier, positioned for tasks where following a long chain of requirements matters more than raw speed. It is described as Google's advanced reasoning model for complex coding, research, analysis, and agentic workflows, building on a multimodal foundation that accepts text, image, video, audio, and PDF inputs while returning text. The preview status signals that the model is still being refined, and Google complements it with grounding tools that let the model pull in fresh information rather than rely solely on its January 2025 knowledge cutoff.

In practical terms, the model is aimed at developers and teams working across large codebases, document collections, and multi-step pipelines where tool use and structured reasoning are central. It is framed as delivering enhanced software engineering performance, improved agentic reliability, and more efficient token usage across complex workflows, which makes it a natural fit for coding assistants, research aides, and orchestrated agent systems. Third-party tooling such as Kilo Code ranks it at position 78 on its Code Mode leaderboard, reflecting real-world usage patterns rather than headline benchmark numbers, and the broad multimodal intake allows a single model to handle mixed-media analyses that would otherwise require separate components.