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OpenAI · Balanced

OpenAI o3

Added Apr 16, 2025

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Use in the app

OpenAI o3 is a reasoning model for complex analytical, coding, mathematical, and scientific tasks.

  • Reasoning
Input
Text
Output
Text
Reasoning effort
low · medium · high
Discovery tier
Balanced

Pricing

USD per 1M tokens
Input
$2.00
Output
$8.00
Cache read
$1.00

Reference prices as published by the model provider. API example

Specifications

Context window
200K
Max output
100K
Average output (7 days)
205 tokens
Longer than 22% of 468 models

Side by side

OpenAI o3 compared

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

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OpenAI o3OpenAIThis modelGPT 6 Luna ProOpenAIRemove
ProviderOpenAIOpenAI
Discovery tierBalancedEfficient
AddedApr 16, 2025Sep 22, 2026
Limits
Context window200K1.05MBest
Max output100K128KBest
Average output205 tokens2.8K tokens
Pricing, USD per 1M tokens
Input$2.00$0.10Best
Output$8.00$0.50Best
Cache read$1.00$0.01Best
Cache write—$0.13
Performance
Throughput—245.6 tok/s
Time to first token—22.2 s
Request success (24h)—100.0%
Benchmark indexes
Intelligence Index20.2—
Math Index88.3—
Capabilities
ReasoningYesYes
ToolsNoYes
VisionNoYes
Structured outputNoYes
PDF inputNoYes
Reasoning effortlow, medium, highlow, medium, high, xhigh, max

Public evaluations

Benchmarks

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

  • OpenAI o3
  • GPT 6 Luna Pro

Intelligence Index

  • OpenAI o320.2
  • GPT 6 Luna Pro—

OpenAI o3: Better than 50% of 326 scored models

3.8Catalog models by score55.1

Indexes

  • Math Index

    Composite of the math evaluations

    • OpenAI o3: 88.3
    • GPT 6 Luna Pro: —

Document reasoning

  • AA-LCRv1.1

    Reasoning across long documents

    • OpenAI o3: 74.7%
    • GPT 6 Luna Pro: —

Reasoning and knowledge

  • Humanity’s Last Exam

    Expert-level questions across academic fields

    • OpenAI o3: 20.1%
    • GPT 6 Luna Pro: —

  • GPQA Diamond

    Graduate-level science questions

    • OpenAI o3: 82.7%
    • GPT 6 Luna Pro: —

  • MMLU-Pro

    Multi-subject knowledge and reasoning

    • OpenAI o3: 85.3%
    • GPT 6 Luna Pro: —

  • IFBench

    Following precise output instructions

    • OpenAI o3: 71.4%
    • GPT 6 Luna Pro: —

Coding

  • LiveCodeBench

    Recent competitive programming problems

    • OpenAI o3: 80.8%
    • GPT 6 Luna Pro: —

Math

  • AIME 2025

    Competition mathematics, 2025 problems

    • OpenAI o3: 88.3%
    • GPT 6 Luna Pro: —

  • AIME

    Competition mathematics

    • OpenAI o3: 90.3%
    • GPT 6 Luna Pro: —

  • MATH-500

    Competition math problems

    • OpenAI o3: 99.2%
    • GPT 6 Luna Pro: —

Legacy evaluations

  • Terminal-Bench Hard

    Earlier terminal task suite

    • OpenAI o3: 37.1%
    • GPT 6 Luna Pro: —

  • τ²-Bench Telecom

    Tool use in a customer-support simulation

    • OpenAI o3: 80.7%
    • GPT 6 Luna Pro: —

  • AA-LCR (unversioned)

    Long-context reasoning, earlier grading

    • OpenAI o3: 74.7%
    • GPT 6 Luna Pro: —

Scores from Artificial Analysis, updated Oct 26, 2026. 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/o3",
    "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/o3",
    messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)

OpenAI

Other OpenAI models, starting with the same family.