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Gemini 3.1 Pro Preview

Google · Gemini 3

Google's current high-end Gemini preview model for multimodal reasoning, agentic workflows, and long-context analysis.

Part of Gemini Pro family · Other versions: Gemini 3 Pro (Preview) , Gemini 2.5 Pro
Type
multimodal
Context
1M tokens
Max Output
66K tokens
Status
preview
Input
$2/1M tok
Output
$12/1M tok
API Access
Yes
License
proprietary
multimodal long-context reasoning coding vision audio preview
Released March 2026 · Updated March 6, 2026

Overview

Freshness note: Model capabilities, limits, and pricing can change quickly. This profile is a point-in-time snapshot last verified on February 22, 2026.

Gemini 3.1 Pro Preview is Google’s current high-end Gemini preview model, positioned as the migration target for the deprecated Gemini 3 Pro Preview. It is aimed at multimodal understanding, agentic capabilities, coding-heavy workflows, and long-context reasoning where teams want the newest Google model behavior before a stable release arrives.

Unlike Gemini 2.5 Pro, Gemini 3.1 Pro Preview is still a preview model. That means behavior, pricing, and lifecycle guarantees can change faster than on stable Gemini 2.5 tiers, so production teams should use stronger evaluation and fallback discipline.

Capabilities

Gemini 3.1 Pro Preview is one of Google’s broadest capability models:

  • Native multimodal understanding across text, images, audio, and video — all processed in a single context rather than through separate pipelines.
  • 1M-token context enables very large codebase analysis, long document review, and broad multimodal evidence synthesis in a single pass.
  • Strong reasoning and coding performance, competitive with top-tier models on benchmarks and real-world development tasks.
  • Grounded generation with the ability to cite sources and integrate with Google Search for factual accuracy.
  • Structured output support for JSON, function calling, and tool use in agentic workflows.

The key practical distinction is not raw scale beyond stable Gemini 2.5 Pro, but newer preview-tier model behavior for harder multimodal and agentic tasks.

Technical Details

Google’s current pricing documentation positions Gemini 3.1 Pro Preview as the newest premium preview model:

  • 1,048,576 token input window.
  • 65,536 max output tokens.
  • Native support for text, image, audio, and video input modalities.
  • Text and structured output (JSON, function calls).
  • Built-in grounding with Google Search and code execution tools.

The model is available through Google AI Studio and Vertex AI style deployment paths where preview models are enabled.

Pricing & Access

Current API pricing (per 1M tokens, for prompts up to 200K tokens):

  • Input: $2.00
  • Output: $12.00

Pricing rises above 200K-token prompts, and preview lifecycle risk is higher than on Gemini 2.5 Pro. Context caching and batch paths are available, which matters for retrieval-heavy or large-prefix workflows.

Access options:

  • Google AI Studio
  • Google Cloud Vertex AI deployment paths
  • Google Gemini API integrations that allow preview-model usage

For teams already on Google Cloud, Vertex AI remains the most controlled path for preview adoption and governance.

Best Use Cases

Gemini 3.1 Pro Preview is strongest in scenarios that benefit from Google’s newest preview-tier multimodal reasoning:

  • Whole-codebase analysis and refactoring where fitting a large repo slice in context reduces chunking complexity.
  • Long document review — contracts, research papers, regulatory filings — in a single prompt.
  • Multimodal workflows combining images, audio, or video with text analysis.
  • Research and synthesis across large collections of sources.
  • Applications that benefit from grounded, citation-backed responses via Search integration.

Less ideal for latency-sensitive, short-context tasks where Gemini 2.5 Flash or Flash-Lite deliver comparable quality at lower cost and faster speeds.

Comparisons

  • Claude Opus 4.6 (Anthropic): Opus is a strong alternative for instruction-heavy enterprise reasoning; Gemini tends to differentiate on first-party multimodal breadth.
  • GPT-5.4 (OpenAI): Competitive on reasoning and coding, with stronger OpenAI-native tooling around ChatGPT and Codex.
  • Gemini 2.5 Flash (Google): Much faster and cheaper for high-throughput tasks, but 3.1 is the better choice when reasoning depth and context length are the priority.