Google: Gemini 3.1 Pro Preview

google/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...

Modalities

In / out price

$2 / $12 per 1M

Context

1.05M

Released

Feb 19, 2026

Why use Gemini 3.1 Pro Preview

Understands images
Understands audio
Reads PDFs and other files
Step-by-step reasoning mode
Tool and function calling (agent-ready)
Structured (JSON) outputs
Very long context: whole books or codebases in one prompt

Pricing

Input	$2 / 1M tokens
Output	$12 / 1M tokens
Cached input (read)	$0.2 / 1M tokens
Cache write	$0.38 / 1M tokens
Image input	$2 / 1M tokens

List prices via OpenRouter, checked daily. Real cost depends on the provider and on reasoning tokens.

How it ranks

Intelligence index29.7

Coding index68.8

Agentic index8.2

Source: Artificial Analysis (artificialanalysis.ai) via OpenRouter (openrouter.ai/rankings).

Cost calculator

Pick a task, set how often you run it, and compare what it costs on each model.

TaskInput tokens≈ 602 wordsOutput tokens≈ 1,504 wordsRuns per month

Input served from cache: 0%Repeated prompts (same instructions or document) are billed at the cheaper cache-read price where the model supports it.

Model	Per run	Per month	Per 1,000 runs
Google: Gemini 3.1 Pro Preview	$0.026	$25.60	$25.60

Estimates from list prices via OpenRouter; real bills vary by provider and reasoning tokens.

Will it fit? Context window simulator

Each square is about one page (500 words). Colored squares are your content; grey squares are free space in the model's context window.

Your content

Novel (90,000 words)

Total: about 120,000 tokens (≈ 90,226 words). Token counts are estimates.

Models

Zoom (square size): 6pxZoom out to see a whole million-token window at once.