GPT-5.1 API

openai/gpt-5-1
GPT-5.1 is an optimized iteration that focuses on refining usability, enhancing communication capabilities, and delivering higher-quality results.
Context
400K tokens
Input
$1.625 / 1M tokens
Output
$13 / 1M tokens
Released
Nov 14, 2025

How to use GPT-5.1 API

Install any OpenAI-compatible SDK, point it at api.aimlapi.com/v1, and set the model to openai/gpt-5-1.
import requests

r = requests.post(
    "https://api.aimlapi.com/v1/chat/completions",
    headers={"Authorization": "Bearer " + AIMLAPI_KEY},
    json={
      "model": "openai/gpt-5-1",
      "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": "openai/gpt-5-1",
    "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":"openai/gpt-5-1","messages":[{"role":"user","content":"Hello!"}]}'

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

GPT-5.1 API Pricing

TypePrice
Input
$1.625 / 1M tokens
Output
$13 / 1M tokens
Cached input
$0.1625 / 1M tokens

GPT-5.1 Benchmarks

BenchmarkScoreWhat it measuresSourceRetrieved
SWE-bench Verified
76.3%
Resolving verified real GitHub issuesSourceJuly 12, 2026
GPQA Diamond
88.1%
Google-proof graduate science questions (hardest subset)SourceJuly 12, 2026
Intelligence
24.7
Composite score across standardised reasoning, knowledge and problem-solving evaluations, measured independently by Artificial AnalysisSourceSeptember 12, 2026
Coding
49.4
Composite score across standardised coding evaluations, measured independently by Artificial AnalysisSourceSeptember 12, 2026
Math
94
Composite score across standardised mathematics evaluations, measured independently by Artificial AnalysisSourceSeptember 12, 2026

GPT-5.1 vs other models

ModelInputOutputContextBest for
GPT-5.1
This page
$1.625 / 1M tokens
$13 / 1M tokens
400K tokens
Reasoning + agents
$6.5 / 1M tokens
$39 / 1M tokens
1M 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
1M tokens
Reasoning + agents

Frequently asked questions

GPT-5.1 has a 400,000 tokens context window and can return up to 128,000 tokens.

GPT-5.1 takes image, text as input and returns text.

Use openai/gpt-5-1 as the model id. Requests go to https://api.aimlapi.com/v1/chat/completions.

GPT-5.1 is priced at input $1.625 / 1M tokens, output $13 / 1M tokens, cached input $0.1625 / 1M tokens.

Yes, GPT-5.1 can stream responses as they are generated.

Yes, GPT-5.1 accepts image input alongside text.

GPT-5.1 was built by OpenAI.

Send requests to https://api.aimlapi.com/v1/chat/completions using the model id openai/gpt-5-1.

Yes, it supports function calling, parallel tool calls, and structured outputs.

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