OpenAI: gpt-5-pro API
The "Professional/Research-grade" flagship snapshot of the GPT-5 series released in August 2025. Specifically engineered for the $200/month ChatGPT Pro tier, it maximizes "inference compute." It can handle complex tasks involving thousands of discrete steps via extended Chain-of-Thought (e.g., end-to-end architecture planning or interdisciplinary scientific proofing) while significantly reducing hallucination rates.
- Context window: 400,000 tokens
- Max output: 272,000 tokens
- Input: text, image
- Output: text
- Reasoning: Supported
- Tool calling: Supported
- File input: Supported
- Released: 2025-08-07
- Knowledge cutoff: 2024-09-30
Frequently Asked Questions
What is the context window of gpt-5-pro?
gpt-5-pro supports a context window of up to 400,000 tokens.
Does gpt-5-pro support function calling?
Yes. gpt-5-pro supports tool / function calling.
Does gpt-5-pro support reasoning?
Yes. gpt-5-pro is a reasoning-capable model.
What is the knowledge cutoff of gpt-5-pro?
The knowledge cutoff of gpt-5-pro is 2024-09-30.