What is the context window of OpenAI: o3 Pro?

OpenAI: o3 Pro supports a context window of 200K tokens.

Is OpenAI: o3 Pro free to use?

OpenAI: o3 Pro is a paid model. It costs $20.00 per million input tokens and $80.00 per million output tokens.

How is LLM API pricing calculated?

LLM pricing has two components: input tokens (everything you send) and output tokens (what the model generates). Total cost = (prompt tokens × input rate + output tokens × output rate) / 1,000,000 × number of requests.

OpenAI: o3 Pro API Pricing — $20.00 Input / $80.00 Output per 1M Tokens

Q: How much does OpenAI: o3 Pro cost?

OpenAI: o3 Pro costs $20.00 per million input tokens and $80.00 per million output tokens via OpenRouter. Pricing was last updated Oct 29, 2026.

OpenAI: o3 Pro by OpenAI — $20.00 input / $80.00 output per 1M tokens via OpenRouter. Context: 200K tokens. Pricing last updated Oct 29, 2026.

Input / 1M tokens

$20.00

Output / 1M tokens

$80.00

Provider

OpenAI

Context window

200K tokens

Via

OpenRouter

Cost at common usage volumes

Usage	Daily	Monthly
Chatbot (100/day)	$11.00	$330.00
Small app (1K/day)	$60.00	$1800.00
Mid-scale (10K/day)	$800.00	$24000.00
Large scale (100K/day)	$18000.00	$540000.00

Model ID: openai/o3-pro
Data source: OpenRouter public API — updated Oct 29, 2026.

← Full cost calculator Compare models →

About OpenAI: o3 Pro

OpenAI: o3 Pro is an LLM developed by OpenAI. Input costs $20.00 per million tokens and output costs $80.00 per million tokens via OpenRouter. It supports a context window of 200K tokens.

Pricing Details

Via the OpenRouter API:

Input tokens: $20.00 per 1 million tokens
Output tokens: $80.00 per 1 million tokens

A token is roughly 0.75 words. For context: a typical user message of 100 words is approximately 133 tokens; a 500-word system prompt is about 650 tokens.

How Much Does OpenAI: o3 Pro Cost?

For a typical chatbot application (1,000 requests/day, 1,000 prompt tokens and 500 output tokens per request):

Daily cost: $60.0000
Monthly cost: $1800.000

Accessing OpenAI: o3 Pro via OpenRouter

OpenRouter provides a unified API for 200+ LLMs including OpenAI: o3 Pro. You can use it with any OpenAI-compatible SDK by setting the base URL to https://openrouter.ai/api/v1 and using your OpenRouter API key. The model ID is openai/o3-pro.

Compare OpenAI: o3 Pro with Other Models

Use the AI Model Cost Comparison tool to compare OpenAI: o3 Pro against GPT-4o, Claude 3.5 Sonnet, Gemini 1.5 Pro, or any other model side by side. Or use the LLM API Cost Calculator to browse all 456+ models sorted by cost for your specific usage.

Frequently Asked Questions

Yes. OpenAI: o3 Pro is available on OpenRouter with the model ID openai/o3-pro. OpenRouter provides a unified API compatible with OpenAI's SDK format.