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OpenAI API

o3 on OpenAI API

o3 · OpenAI

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Last refreshed 2026-05-10. Next refresh: weekly.

Why use o3 on OpenAI API?

OpenAI API offers o3 with pay-as-you-go pricing at $2.00/1M input tokens. OpenAI is a leading AI research and deployment company dedicated to developing safe and beneficial artificial general intelligence (AGI) for humanity.

Compare o3 across 2 providers to find the best fit for your use case
Input / 1M
$2.00
Output / 1M
$8.00
Cache
read $0.50
Batch
-50% · in $1.00 / out $4.00

Setup recipe

Python + curl
Install
pip install openai
Auth
export OPENAI_API_KEY=...
Call
import os
from openai import OpenAI
client = OpenAI()  # reads OPENAI_API_KEY from env
response = client.chat.completions.create(
Model ID
o3

Request example

import os
from openai import OpenAI

client = OpenAI()  # reads OPENAI_API_KEY from env
response = client.chat.completions.create(
    model="o3",
    messages=[{"role": "user", "content": "Hello"}]
)
print(response.choices[0].message.content)

Gotchas

  • Use the model slug directly, e.g. "gpt-4o" or "gpt-4.1-mini".
  • The examples expect OPENAI_API_KEY; rename it only if your application config maps the new variable.

Compare o3 Across Providers

ProviderInput (per 1M)Output (per 1M)
OpenAI API$2.00$8.00
OpenRouter$2.00$8.00

Pricing

TypePrice (per 1M)
Input tokens$2.00
Output tokens$8.00

Capabilities

ReasoningStructured OutputsCode ExecutionPrompt CachingBatch API

About o3

OpenAI o3 reasoning model with advanced multi-step problem-solving capabilities.

FAQ

What does o3 cost on OpenAI API?

On OpenAI API, o3 costs $2.00 per 1M input tokens and $8.00 per 1M output tokens.

What is the context window for o3 on OpenAI API?

o3 supports a 200,000 token context window on OpenAI API.

How does OpenAI API compare to other o3 providers?

o3 is available from 2 providers. The cheapest input pricing is $2.00/1M tokens from OpenAI API.

What API model ID do I use for o3 on OpenAI API?

Use the model ID o3 when calling OpenAI API's API.

Who created o3?

o3 was created by OpenAI as part of the o3 model family.

Is o3 open source?

o3 is not open source; the seed data lists it as proprietary.

Get Started

Model Specs

Released2025-03-31
Context200K
ArchitectureDecoder Only

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