Gemini 3.1 Pro API

google/gemini-3.1-pro-preview
Gemini 3.1 Pro API is here. Smarter reasoning. Deeper context.
Context
1M tokens
Input
$2.6 / 1M tokens
Output
$15.6 / 1M tokens
Released
Feb 25, 2026

How to use Gemini 3.1 Pro API

Install any OpenAI-compatible SDK, point it at api.aimlapi.com/v1, and set the model to google/gemini-3.1-pro-preview.
import requests

r = requests.post(
    "https://api.aimlapi.com/v1/chat/completions",
    headers={"Authorization": "Bearer " + AIMLAPI_KEY},
    json={
      "model": "google/gemini-3.1-pro-preview",
      "messages": [
        {
          "role": "user",
          "content": "Hello!"
        }
      ]
    },
)
print(r.json())
const r = await fetch("https://api.aimlapi.com/v1/chat/completions", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.AIMLAPI_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "model": "google/gemini-3.1-pro-preview",
    "messages": [
      {
        "role": "user",
        "content": "Hello!"
      }
    ]
  }),
});
console.log(await r.json());
curl -X POST https://api.aimlapi.com/v1/chat/completions \
  -H "Authorization: Bearer $AIMLAPI_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"google/gemini-3.1-pro-preview","messages":[{"role":"user","content":"Hello!"}]}'

OpenAI-compatible — swap the base URL and it works with your existing SDK.

Gemini 3.1 Pro API Pricing

TypePrice
Input
$2.6 / 1M tokens
Output
$15.6 / 1M tokens
Cached input
$0.65 / 1M tokens

Gemini 3.1 Pro Benchmarks

BenchmarkScoreWhat it measuresSourceRetrieved
Humanity's Last Exam
44.4%
Expert-level questions across many domainsSourceJuly 13, 2026
Terminal-Bench
68.5%
Autonomous shell/terminal task completionSourceJuly 13, 2026
SWE-bench Verified
80.6%
Resolving verified real GitHub issuesSourceJuly 13, 2026
GPQA Diamond
94.3%
Google-proof graduate science questions (hardest subset)SourceJuly 13, 2026
Intelligence
30.4
Composite score across standardised reasoning, knowledge and problem-solving evaluations, measured independently by Artificial AnalysisSourceSeptember 12, 2026
Coding
68.8
Composite score across standardised coding evaluations, measured independently by Artificial AnalysisSourceSeptember 12, 2026

Gemini 3.1 Pro vs other models

ModelInputOutputContextBest for
$2.6 / 1M tokens
$15.6 / 1M tokens
1M tokens
Coding + agents
$6.5 / 1M tokens
$39 / 1M tokens
1.05M tokens
Reasoning + agents
$2.6 / 1M tokens
$13 / 1M tokens
1M tokens
Balanced coding + agents
$3.9 / 1M tokens
$19.5 / 1M tokens
1M tokens
Long-context, multimodal & agentic workflows
$0.65 / 1M tokens
$3.9 / 1M tokens
1.05M tokens
Reasoning + agents

Frequently asked questions

Gemini 3.1 Pro has a 1,000,000 tokens context window and can return up to 65,536 tokens.

Gemini 3.1 Pro takes image, text as input and returns text.

Use google/gemini-3.1-pro-preview as the model id. Requests go to https://api.aimlapi.com/v1/chat/completions.

Gemini 3.1 Pro became available on February 25, 2026.

Gemini 3.1 Pro is priced at input $2.6 / 1M tokens, output $15.6 / 1M tokens, cached input $0.65 / 1M tokens.

Yes, Gemini 3.1 Pro can stream responses as they are generated.

Yes, Gemini 3.1 Pro accepts image input alongside text.

Gemini 3.1 Pro was built by Google.

It is described as a reasoning model optimized for software engineering and agentic workflows.

Yes, it supports function calling, tool use, and parallel tool calls, along with structured output.

Start building with Gemini 3.1 Pro

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