OpenAI: gpt-5-nano API
The most lightweight version in the GPT-5 family, released in August 2025. Designed to provide instant responses with minimal computational overhead, it is optimized for simple instruction following, high-throughput classification, real-time summarization, and mobile/edge deployments. While less powerful in complex reasoning, it offers dominant performance for handling thousands of concurrent requests.
- 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: 2024-05-31
Frequently Asked Questions
What is the context window of gpt-5-nano?
gpt-5-nano supports a context window of up to 400,000 tokens.
Does gpt-5-nano support function calling?
Yes. gpt-5-nano supports tool / function calling.
Does gpt-5-nano support reasoning?
Yes. gpt-5-nano is a reasoning-capable model.
What is the knowledge cutoff of gpt-5-nano?
The knowledge cutoff of gpt-5-nano is 2024-05-31.