OpenAI: GPT-5 API
OpenAI's 5th-generation integrated flagship model. It unifies the GPT series (LLM) and o-series (Reasoning) at the architectural level, combining native Chain-of-Thought with comprehensive multimodality. Featuring an automated routing mechanism, it autonomously decides whether to engage deep thinking mode based on task complexity.
- Context window: 400,000 tokens
- Max output: 128,000 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?
GPT-5 supports a context window of up to 400,000 tokens.
Does GPT-5 support function calling?
Yes. GPT-5 supports tool / function calling.
Does GPT-5 support reasoning?
Yes. GPT-5 is a reasoning-capable model.
What is the knowledge cutoff of GPT-5?
The knowledge cutoff of GPT-5 is 2024-09-30.