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Gemini 3.1 Pro Preview

GoogleReleased Feb 19, 2026

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...

Try in playground
Context window
1.0M tokens
Max output
66K tokens
Input
audio, file, image, text, video
Output
text
Tokenizer
Gemini
Released
Feb 19, 2026
Reasoning
always on

Pricing

Per 1M tokens. The provider price and our flat 3% fee are separate columns — what you pay is their sum.

Per 1M tokensProvider+ 3% feeYou pay
Input$2.00$0.060$2.06
Output$12.00$0.360$12.36
Cache read$0.200$0.0060$0.206
Cache write$0.375$0.011$0.386

Benchmarks

Artificial Analysis

Intelligence index
46.5
Coding index
68.8
Agentic index
21.4

Design Arena

CategoryEloWin rateRank
agenticgamedevagents114943.8%#8
agentichtmlslidesagents122655.8%#5
agenticslidesagents111233.8%#8
agenticslides(html)agents121954.4%#5
agenticslides(python-pptx)agents110733.9%#8
androidnativeagents105939.2%#25
Full-stackagents113945%#16
godotgamedevagents122053.6%#6
htmlslidesagents120952.9%#6
Mobile appsagents117646.6%#22
pptxslidesagents111034.1%#8
python-pptxslidesagents110931.9%#9
Web appsagents119648.2%#13
3Dmodels130361.4%#17
ASCII artmodels131463.4%#4
Codemodels129064.2%#18
Data vizmodels127060.6%#20
Game devmodels126454.6%#26
SVGmodels134770.3%#2
UI componentsmodels132268.1%#8
Websitesmodels129464.3%#15

Head-to-head preference voting. How we filter and rank

Supported parameters

  • include_reasoning
  • max_tokens
  • reasoning
  • response_format
  • seed
  • stop
  • structured_outputs
  • temperature
  • tool_choice
  • tools
  • top_p

Call it

OpenAI-compatible: point your SDK at api.openkey.ai/v1 and use model google/gemini-3.1-pro-preview.

Code sample language
curl https://api.openkey.ai/v1/chat/completions \
  -H "Authorization: Bearer $OPENKEY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "google/gemini-3.1-pro-preview",
    "messages": [{"role": "user", "content": "Hello"}]
  }'
import os
from openai import OpenAI

client = OpenAI(
    base_url="https://api.openkey.ai/v1",
    api_key=os.environ["OPENKEY_API_KEY"],
)

completion = client.chat.completions.create(
    model="google/gemini-3.1-pro-preview",
    messages=[{"role": "user", "content": "Hello"}],
)
print(completion.choices[0].message.content)
import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.openkey.ai/v1",
  apiKey: process.env.OPENKEY_API_KEY,
});

const completion = await client.chat.completions.create({
  model: "google/gemini-3.1-pro-preview",
  messages: [{ role: "user", content: "Hello" }],
});
console.log(completion.choices[0].message.content);

Questions

How much does Gemini 3.1 Pro Preview cost via API?
Through OpenKey, Gemini 3.1 Pro Preview costs $2.06 per 1M input tokens and $12.36 per 1M output tokens. That is the provider price ($2.00 / $12.00) plus a flat 3% fee — nothing else.
What is Gemini 3.1 Pro Preview's context window?
Gemini 3.1 Pro Preview accepts up to 1.0M tokens of context and returns up to 66K tokens per request.
Is Gemini 3.1 Pro Preview OpenAI-compatible?
Yes. Send requests to OpenKey's /v1/chat/completions endpoint with model "google/gemini-3.1-pro-preview" using any OpenAI SDK — only the base URL and API key change.
What inputs does Gemini 3.1 Pro Preview support?
Gemini 3.1 Pro Preview accepts audio, file, image, text, video input and produces text output.

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