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OpenAI · Frontier

GPT 5

Added Aug 7, 2025

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Use in the app

GPT-5 is OpenAI's most advanced model, offering major improvements in reasoning, code quality, and user experience. It handles complex coding tasks with minimal prompting, provides clear explanations, and introduces enhanced agentic capabilities. Designed for logic and multi-step tasks.

  • Reasoning
  • Tools
  • Vision
  • Structured output
  • PDF input
Input
Text, Images
Output
Text
Reasoning effort
minimal · 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)
411 tokens
Longer than 41% of 468 models

Side by side

GPT 5 compared

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

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GPT 5OpenAIThis modelGPT 5.5OpenAIRemove
ProviderOpenAIOpenAI
Discovery tierFrontierFrontier
AddedAug 7, 2025Apr 23, 2026
Limits
Context window400K1.05MBest
Max output128K128K
Average output411 tokens490 tokens
Pricing, USD per 1M tokens
Input$1.25Best$5.00
Output$10.00Best$30.00
Cache read$0.13Best$0.50
Performance
Request success (24h)—100.0%
Benchmark indexes
Intelligence Index23.038.4Best
Coding Index37.874.9Best
Math Index94.3—
Capabilities
ReasoningYesYes
ToolsYesYes
VisionYesYes
Structured outputYesYes
PDF inputYesYes
Reasoning effortminimal, low, medium, highnone, low, medium, high, xhigh

Public evaluations

Benchmarks

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

  • GPT 5
  • GPT 5.5

Intelligence Index

  • GPT 523.0
  • GPT 5.538.4

GPT 5 tested at high reasoning effort

GPT 5: Better than 57% of 326 scored models

3.8Catalog models by score55.1

Indexes

  • Coding Index

    Composite of the coding evaluations

    • GPT 5: 37.8
    • GPT 5.5: 74.9Top

  • Math Index

    Composite of the math evaluations

    • GPT 5: 94.3
    • GPT 5.5: —

Agentic work

  • AutomationBench-AA

    Workflow automation, penalized for guardrail violations

    • GPT 5: —
    • GPT 5.5: 47.3%

  • AutomationBench-AA tasks completed

    Workflows finished end to end without a guardrail violation

    • GPT 5: —
    • GPT 5.5: 19.6%

  • AA-Briefcasev1.1

    Agentic knowledge work, rated head to head

    • GPT 5: —
    • GPT 5.5: 1,136 Elo

  • GDPval-AAv2.1

    Economically valuable occupational tasks, rated head to head

    • GPT 5: 918 Elo
    • GPT 5.5: 1,351 EloTop

Document reasoning

  • GDP.pdf

    Professional reasoning over PDF documents, all-pass rate

    • GPT 5: —
    • GPT 5.5: 21.2%

  • AA-LCRv1.1

    Reasoning across long documents

    • GPT 5: 78.2%
    • GPT 5.5: 84.3%Top

  • MLCR-AA

    Long-context reasoning over medical records

    • GPT 5: —
    • GPT 5.5: 28.9%

Reasoning and knowledge

  • Humanity’s Last Exam

    Expert-level questions across academic fields

    • GPT 5: 28.5%
    • GPT 5.5: 45.8%Top

  • GPQA Diamond

    Graduate-level science questions

    • GPT 5: 85.4%
    • GPT 5.5: 93.5%Top

  • MMLU-Pro

    Multi-subject knowledge and reasoning

    • GPT 5: 87.1%
    • GPT 5.5: —

  • IFBench

    Following precise output instructions

    • GPT 5: 73.1%
    • GPT 5.5: 75.9%Top

Coding

  • Terminal-Benchv4.0

    Practical software engineering in a terminal

    • GPT 5: —
    • GPT 5.5: 14.6%

  • SciCode

    Scientific computing in Python

    • GPT 5: —
    • GPT 5.5: 55.8%

  • LiveCodeBench

    Recent competitive programming problems

    • GPT 5: 84.6%
    • GPT 5.5: —

Math

  • AIME 2025

    Competition mathematics, 2025 problems

    • GPT 5: 94.3%
    • GPT 5.5: —

  • AIME

    Competition mathematics

    • GPT 5: 95.7%
    • GPT 5.5: —

  • MATH-500

    Competition math problems

    • GPT 5: 99.4%
    • GPT 5.5: —

Legacy evaluations

  • Terminal-Bench Hard

    Earlier terminal task suite

    • GPT 5: 32.6%
    • GPT 5.5: 60.6%Top

  • τ²-Bench Telecom

    Tool use in a customer-support simulation

    • GPT 5: 84.8%
    • GPT 5.5: 93.9%Top

  • AA-LCR (unversioned)

    Long-context reasoning, earlier grading

    • GPT 5: 78.2%
    • GPT 5.5: 84.3%Top

Scores from Artificial Analysis, updated Oct 26, 2026. GPT 5 was tested at high reasoning effort; compare scores measured at the same effort.Artificial Analysis

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",
    "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",
    messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)

OpenAI

Other OpenAI models, starting with the same family.