OpenAI · Frontier

OpenAI o3-pro (2025-06-10)

Added Jan 1, 2024

Use in the app

The pro version of the already fantastic o3.

Reasoning
Tools
Structured output

Input: Text
Output: Text
Reasoning effort: low · medium · high
Discovery tier: Frontier

Pricing

USD per 1M tokens

Input: $22.00
Output: $88.00
Cache read: $11.00

Reference prices as published by the model provider. API example

Specifications

Context window: 200K
Max output: 100K

Side by side

Compare models

Put OpenAI o3-pro (2025-06-10) next to up to three other models. The comparison stays in the link, so you can share it.

TryMiMo V2.5 Thinking Kimi K2 Thinking Gemini 3.5 Flash Lite All 3

Public evaluations

Benchmarks

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

Intelligence Index

21.9

Better than 53% of 326 scored models

3.8Catalog models by score55.1

Reasoning and knowledge

GPQA Diamond
84.5%
Graduate-level science questions
Better than 59% of 291 scored models

Scores from Artificial Analysis, updated Oct 26, 2026.

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-pro-2025-06-10",
    "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-pro-2025-06-10",
    messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)

OpenAI

Other OpenAI models, starting with the same family.

Reasoning and knowledge

GPQA Diamond