Overview
o3 is a reasoning model from OpenAI for complex tasks. OpenAI documents it for math, science, coding, visual reasoning and technical writing. It accepts text and image input, returns text, supports tool calling and structured output, and has a 200,000-token context window.
It has a 200,000-token context window and can generate up to 100,000 output tokens. It accepts text and image input and returns text. Its knowledge cutoff is June 1, 2024, and it was released on April 16, 2025.
Capabilities
o3 supports reasoning, tool calling, structured output and image understanding. It reads text and image input together and returns text.
The areas OpenAI names for it are math, science, coding and visual reasoning, plus technical writing, so it covers both analytical work and the clear written explanation of its results.
Pricing
o3 is priced at $2.00 per 1M input tokens and at $8.00 per 1M output tokens. Cached input reads are priced at $0.50 per 1M tokens.
o3 is available through RealRelay's OpenAI-compatible API.
Use cases
Use o3 for problems that need careful reasoning, such as a multi-step math or science question, a coding task that spans several files or a technical report that must explain its logic.
Visual reasoning lets it read charts, diagrams and screenshots as part of the question, and tool calling lets it fetch data or run steps before it answers.
What is o3?
o3 is an OpenAI reasoning model for complex tasks in math, science, coding and visual reasoning, with image input and a 200,000-token context window.
How much does o3 cost?
o3 is priced at $2.00 per 1M input tokens and at $8.00 per 1M output tokens. Cached input reads are priced at $0.50 per 1M tokens.
What is the context window and maximum output of o3?
o3 has a 200,000-token context window and can generate up to 100,000 output tokens.
What inputs and outputs does o3 support?
o3 accepts text and image input and returns text.
What capabilities does o3 support?
o3 supports reasoning, tool calling, structured output and image understanding.
When was o3 released?
o3 was released on April 16, 2025.
How do I call o3 via the API?
Call o3 through RealRelay's OpenAI-compatible API using the model ID openai/o3.