Is GPT-5 Mini available on FastMetal?

Not at the moment. GPT-5.6 Sol, from the same lab, is available on the FastMetal API today.

What is the context window of GPT-5 Mini?

400,000 tokens, shared between the prompt and the response.

How does GPT-5 Mini rank?

#106 on the public arena's Japanese board (ELO 1,364). Ranks move as the leaderboard is updated.

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openai/gpt-5-mini

Not Available

GPT-5 Mini

GPT-5 Mini is a compact version of GPT-5, designed to handle lighter-weight reasoning tasks. It provides the same instruction-following and safety-tuning benefits as GPT-5, but with reduced latency and cost. GPT-5 Mini is the successor to OpenAI's o4-mini model.

8/7/2025

400,000 tokens

#86 Vision (Overall)

Specifications

Modalities

Input

text

image

file

Output

text

Supported Parameters

include_reasoning

max_tokens

reasoning

response_format

seed

structured_outputs

tool_choice

tools

Max Output Tokens

128,000

Reasoning Configuration

Default: Thinking on (effort: medium)
Selectable effort levels: high
medium
low
minimal
Turning thinking off: Not possible (always thinks)

How to control thinking, and what it costs

Frequently asked questions

Is GPT-5 Mini available on FastMetal?: Not at the moment. GPT-5.6 Sol, from the same lab, is available on the FastMetal API today.
What is the context window of GPT-5 Mini?: 400,000 tokens, shared between the prompt and the response.
How does GPT-5 Mini rank?: #106 on the public arena's Japanese board (ELO 1,364). Ranks move as the leaderboard is updated.