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OpenAI · Frontier

GPT 4.1

Added Sep 10, 2025

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Use in the app

GPT 4.1 is the new flagship model from OpenAI. Huge context window (1 mln tokens), outperforms GPT-4o and GPT 4.5 across coding and does very well at understanding large contexts.

  • Tools
  • Vision
  • Structured output
  • PDF input
Input
Text, Images
Output
Text
Discovery tier
Frontier

Pricing

USD per 1M tokens
Input
$2.00
Output
$8.00
Cache read
$0.50

Reference prices as published by the model provider. API example

Specifications

Context window
1M
Max output
32.8K
Average output (7 days)
29 tokens
Longer than 1% of 465 models

Side by side

GPT 4.1 compared

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

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GPT 4.1OpenAIThis modelGPT 5.1OpenAIRemove
ProviderOpenAIOpenAI
Discovery tierFrontierFrontier
AddedSep 10, 2025Nov 13, 2025
Limits
Context window1.05MBest400K
Max output32.77K128KBest
Average output29 tokens294 tokens
Pricing, USD per 1M tokens
Input$2.00$1.25Best
Output$8.00Best$10.00
Cache read$0.50$0.13Best
Performance
Request success (24h)100.0%100.0%
Benchmark indexes
Intelligence Index12.713.3Best
Math Index34.738.0Best
Capabilities
ReasoningNoYes
ToolsYesYes
VisionYesYes
Structured outputYesYes
PDF inputYesYes
Reasoning effort—none, low, medium, high

Public evaluations

Benchmarks

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

  • GPT 4.1
  • GPT 5.1

Intelligence Index

  • GPT 4.112.7
  • GPT 5.113.3

GPT 4.1: Better than 28% of 326 scored models

3.8Catalog models by score55.1

Indexes

  • Math Index

    Composite of the math evaluations

    • GPT 4.1: 34.7
    • GPT 5.1: 38.0Top

Document reasoning

  • AA-LCRv1.1

    Reasoning across long documents

    • GPT 4.1: 68.3%Top
    • GPT 5.1: 45.0%

Reasoning and knowledge

  • Humanity’s Last Exam

    Expert-level questions across academic fields

    • GPT 4.1: 4.2%
    • GPT 5.1: 5.3%Top

  • GPQA Diamond

    Graduate-level science questions

    • GPT 4.1: 66.6%Top
    • GPT 5.1: 64.3%

  • MMLU-Pro

    Multi-subject knowledge and reasoning

    • GPT 4.1: 80.6%Top
    • GPT 5.1: 80.1%

  • IFBench

    Following precise output instructions

    • GPT 4.1: 43.0%
    • GPT 5.1: 43.2%Top

Coding

  • LiveCodeBench

    Recent competitive programming problems

    • GPT 4.1: 45.7%
    • GPT 5.1: 49.4%Top

Math

  • AIME 2025

    Competition mathematics, 2025 problems

    • GPT 4.1: 34.7%
    • GPT 5.1: 38.0%Top

  • AIME

    Competition mathematics

    • GPT 4.1: 43.7%
    • GPT 5.1: —

  • MATH-500

    Competition math problems

    • GPT 4.1: 91.3%
    • GPT 5.1: —

Legacy evaluations

  • Terminal-Bench Hard

    Earlier terminal task suite

    • GPT 4.1: 13.6%
    • GPT 5.1: 22.7%Top

  • τ²-Bench Telecom

    Tool use in a customer-support simulation

    • GPT 4.1: 47.1%Top
    • GPT 5.1: 46.5%

  • AA-LCR (unversioned)

    Long-context reasoning, earlier grading

    • GPT 4.1: 68.3%Top
    • GPT 5.1: 45.0%

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
57.9%
About $1.13 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-4.1",
    "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-4.1",
    messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)

OpenAI

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