NOUMENOpen app
NOUMEN

OpenAI · Frontier

GPT 5.1

Added Nov 13, 2025

Compare models

Choose up to 3 models to compare.1 of 3 chosen

Loading models…

Use in the app

Optimized GPT-5.1 routing for lower latency and higher availability.

  • Reasoning
  • Tools
  • Vision
  • Structured output
  • PDF input
Input
Text, Images
Output
Text
Reasoning effort
none · low · medium · high
Discovery tier
Frontier

Pricing

USD per 1M tokens
Input
$1.25
Output
$10.00
Cache read
$0.13

Reference prices as published by the model provider. API example

Specifications

Context window
400K
Max output
128K
Average output (7 days)
294 tokens
Longer than 31% of 465 models

Side by side

GPT 5.1 compared

Specifications, prices, speed and benchmark scores next to each other. Benchmarks below show every compared model too.

Compare models

Choose up to 3 models to compare.1 of 3 chosen

Loading models…

GPT 5.1OpenAIThis modelDeepSeek V3.1 ThinkingDeepSeekRemove
ProviderOpenAIDeepSeek
Discovery tierFrontierOpen weights
AddedNov 13, 2025Jan 1, 2024
Limits
Context window400KBest128K
Max output128KBest65.54K
Average output294 tokens483 tokens
Pricing, USD per 1M tokens
Input$1.25$0.20Best
Output$10.00$0.70Best
Cache read$0.13—
Performance
Throughput—14.9 tok/s
Time to first token—2.6 s
Request success (24h)100.0%100.0%
Benchmark indexes
Intelligence Index13.313.5Best
Math Index38.089.7Best
Capabilities
ReasoningYesNo
ToolsYesYes
VisionYesNo
Structured outputYesNo
PDF inputYesNo
Reasoning effortnone, low, medium, high—

Public evaluations

Benchmarks

Independent evaluation results, with how each score ranks among the models in the Noumen catalog.

  • GPT 5.1
  • DeepSeek V3.1 Thinking

Intelligence Index

  • GPT 5.113.3
  • DeepSeek V3.1 Thinking13.5

GPT 5.1: Better than 33% of 326 scored models

3.8Catalog models by score55.1

Indexes

  • Math Index

    Composite of the math evaluations

    • GPT 5.1: 38.0
    • DeepSeek V3.1 Thinking: 89.7Top

Document reasoning

  • AA-LCRv1.1

    Reasoning across long documents

    • GPT 5.1: 45.0%
    • DeepSeek V3.1 Thinking: 56.7%Top

Reasoning and knowledge

  • Humanity’s Last Exam

    Expert-level questions across academic fields

    • GPT 5.1: 5.3%
    • DeepSeek V3.1 Thinking: 14.3%Top

  • GPQA Diamond

    Graduate-level science questions

    • GPT 5.1: 64.3%
    • DeepSeek V3.1 Thinking: 77.9%Top

  • MMLU-Pro

    Multi-subject knowledge and reasoning

    • GPT 5.1: 80.1%
    • DeepSeek V3.1 Thinking: 85.1%Top

  • IFBench

    Following precise output instructions

    • GPT 5.1: 43.2%Top
    • DeepSeek V3.1 Thinking: 41.5%

Coding

  • LiveCodeBench

    Recent competitive programming problems

    • GPT 5.1: 49.4%
    • DeepSeek V3.1 Thinking: 78.4%Top

Math

  • AIME 2025

    Competition mathematics, 2025 problems

    • GPT 5.1: 38.0%
    • DeepSeek V3.1 Thinking: 89.7%Top

Legacy evaluations

  • Terminal-Bench Hard

    Earlier terminal task suite

    • GPT 5.1: 22.7%
    • DeepSeek V3.1 Thinking: 25.0%Top

  • τ²-Bench Telecom

    Tool use in a customer-support simulation

    • GPT 5.1: 46.5%Top
    • DeepSeek V3.1 Thinking: 37.4%

  • AA-LCR (unversioned)

    Long-context reasoning, earlier grading

    • GPT 5.1: 45.0%
    • DeepSeek V3.1 Thinking: 56.7%Top

Scores from Artificial Analysis, updated Oct 26, 2026. Artificial Analysis

Live routing data

Performance and reliability

Recent averages across requests routed for this model. Your own speed depends on prompt length, reasoning effort and load.

Prompt cache hits
47.6%
About $0.71 per 1M input tokens with caching
Request success (24h)
100.0%
Reliable

Cache hits are the share of input tokens recently served from a prompt cache across all requests. They are not a forecast of your own hit rate.

Hourly request success · last 72 hoursLowest hour 100.0%
  • Healthy (98% or more)
  • Degraded (90–98%)
  • Down (under 90%)
  • No requests

Developers

Use it through the API

Noumen’s API is OpenAI-compatible: any Chat Completions client works with a base URL and a key.

Read the quickstart
curl https://www.noumen.xyz/api/v1/chat/completions \
  -H "Authorization: Bearer $NOUMEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/gpt-5.1",
    "reasoning_effort": "medium",
    "messages": [{ "role": "user", "content": "Explain this stack trace." }]
  }'
import os
from openai import OpenAI

client = OpenAI(base_url="https://www.noumen.xyz/api/v1", api_key=os.environ["NOUMEN_API_KEY"])
reply = client.chat.completions.create(
    model="openai/gpt-5.1",
    messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)

OpenAI

Other OpenAI models, starting with the same family.