Context Window
GooglefastVisionTool use

Gemini 3.1 Pro Preview

Gemini 3.1 Pro Preview is Google’s frontier reasoning model, delivering enhanced software engineering performance, improved agentic reliability, and more efficient token usage across complex workflows. Building on the multimodal foundation of the Gemini 3 series, it combines high-precision reasoning across text, image, video, audio, and code with a 1M-token context window. Reasoning Details must be preserved when using multi-turn tool calling, see our docs here: https://openrouter.ai/docs/use-ca

1.0M context·~786K words·66K max output
View context detailsCompare with Gemma 7b It
Context window1.0Mtokens
Max output66Ktokens

Context window

This model accepts 1.0M tokens in one request (~786K words of text).

Context window size1.0M tokens
4K32K128K1M10M

What fits in one request

  • Short document
    About 1,500 words of text
    Fits
  • Long document
    About 37K words of text
    Fits
  • Small codebase
    About 150K words of text
    Fits
  • Full novel
    About 375K words of text
    Fits

Specifications

Context size, pricing, and release info in one place.

Context window
1,048,576 tokens (1.0M)
Max output tokens
65,536 tokens (66K)
Speed tier
fast
Provider
Google
Release date
Feb 2026
Input cost
$2.00/M / 1M tokens
Output cost
$12.00/M / 1M tokens
Cached input
$0.200/M / 1M tokens

Capabilities

See which features this model supports, such as vision, tools, and streaming.

Supported (6)
Vision
Supported
Tool use
Supported
Function calling
Supported
Extended thinking
Supported
Streaming
Supported
Prompt caching
Supported
Not supported (2)
Web search
Not supported
Batch API
Not supported

Best for

Jump to a guide or ranking that matches each workload.

ReasoningAI agentsMultimodalLong documentsRAGChatbots

Compare Gemini 3.1 Pro Preview

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Frequently asked questions

Short answers about context size and how this model behaves.

Gemini 3.1 Pro Preview has a context window of 1M tokens (1,048,576 tokens). This million-token window can process entire codebases, long legal documents, or book-length texts in a single pass.

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Powered by Mem0

Use a smaller model.
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Mem0 gives your AI long-term memory so you stop re-sending context on every call. That means you can use a smaller, faster, cheaper model — and still get better answers.

Calculate your savingsLearn about Mem0

Example: a multi-turn chat session

Without Mem0~128K tokens sent
Full history
Repeated info
Old context
With Mem0~20K tokens sent
Key memories
Current turn

80% less to send — works with any model