Google's reasoning-focused Gemini 3.1 Pro preview for coding and complex analysis, with a 1M-token context and $2/$12 per million pricing.

Key specifications

Capability
88.5
Context window
1.0M
Max output
65.5K
Input $/1M
$2.00
Output $/1M
$12.00
License
Proprietary

Inputs and outputs

Recorded modality support shows what this model can accept and produce. An undocumented modality is shown as unknown rather than assumed to be unsupported.

Accepts

  • Text input
  • Image input
  • Video input
  • Audio input
  • PDF input

Produces

  • Text output

Capabilities

ReasoningFunction callingVisionAudioJSON mode

What is Gemini 3.1 Pro Preview?

gemini 3.1 pro preview is Google's frontier-tier reasoning model in the 3.1 generation, the one to reach for when a task needs multiple steps of thinking, not just fast pattern matching. It's built for coding, complex analysis, and agentic problem solving where getting the answer right matters more than shaving a few cents off the bill. Developers building coding assistants, research agents, or anything that chains several reasoning steps together are the target audience.

Context, output, and pricing

The model carries a 1,048,576 token context window with up to 65,536 tokens of output per call — enough room to hold a full codebase excerpt, a long research thread, or a multi-document brief in one request. Input tokens cost $2.00 per million, output tokens $12.00 per million, and cached input is $0.20 per million. That 6x output-to-input price ratio is worth planning around: verbose responses cost real money here, so prompts that ask for concise, structured output pay off more than they would on a cheaper tier.

What it's built to do well

  • Multi-step coding tasks — debugging, refactoring, or reasoning through a change across several files
  • Complex analysis where the model needs to hold a large document or codebase in context
  • Agentic workflows that combine reasoning with function calling
  • Vision-plus-reasoning tasks: reading a screenshot, diagram, or PDF and reasoning about it, not just describing it

How it compares within the 3.1 family

Gemini 3.1 Flash Lite Preview costs $0.25 per million input and $1.50 per million output — an 8x discount on both sides — and posts a capability score of 88.6 against Pro Preview's 88.5. On paper those scores are nearly identical, which is a real signal: for tasks that don't need Pro's depth, Flash Lite is worth testing first, and reserving Pro for the harder end of the workload where multi-step reasoning actually shows up is the more defensible default than routing everything to the most expensive tier.

The honest limitation

As a preview release, pricing, output limits, and availability aren't locked in, and Google can change them before general availability ships. There's no benchmark suite attached to this listing, so treat capability comparisons as a rough signal, not a ranking — run your own eval against your own task before committing a production workload to it.

How to evaluate Gemini 3.1 Pro Preview

Use the recorded facts as a shortlist, then validate the model against representative inputs and production constraints.

Workload fit

Gemini 3.1 Pro Preview is categorized for Audio-text-to-text, Automatic speech recognition, Image-text-to-text, Image-to-text, Text generation, Text-to-text AI models, Video-text-to-text. Its current record accepts text, image, video, audio, pdf and produces text. Confirm file formats, preprocessing, and provider-specific request schemas before implementation.

Capacity and cost

The directory records 1.0M context and 65.5K maximum output. Listed token prices are $2.00 input and $12.00 output per 1M tokens. Treat missing values as unknown and recheck current commercial terms.

Operational behavior

Recorded output speed is — and time to first token is —. Hosting route, region, prompt length, concurrency, and provider load can materially change both measurements.

Evidence boundary

This page separates sourced model facts from incomplete fields. Benchmark evidence is displayed only when its source is linked and verified. Before choosing Gemini 3.1 Pro Preview, test task quality, tool reliability, safety behavior, data controls, rate limits, and total cost on the exact route you intend to use.

Strengths

  • + Registry-backed capabilities
  • + Provider: Google

Limitations

  • Draft record — editorial review required
  • Verify pricing and independent evaluations before approval

Frequently asked questions

Input tokens are $2.00 per million, output tokens are $12.00 per million, and cached input is $0.20 per million tokens.

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