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OpenKey

GPT-5 Mini

OpenAIReleased Aug 7, 2025

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....

Try in playground
Context window
400K tokens
Max output
128K tokens
Input
text, image, file
Output
text
Tokenizer
GPT
Knowledge cutoff
May 31, 2024
Released
Aug 7, 2025
Reasoning
always on

Pricing

Per 1M tokens. The provider price and our flat 3% fee are separate columns — what you pay is their sum.

Per 1M tokensProvider+ 3% feeYou pay
Input$0.250$0.0075$0.258
Output$2.00$0.060$2.06
Cache read$0.025$0.0008$0.026

Benchmarks

Design Arena

CategoryEloWin rateRank
3Dmodels111437.3%#73
ASCII artmodels117345.4%#33
Codemodels116443.8%#64
Data vizmodels116743.5%#62
Game devmodels119446.5%#54
SVGmodels114946%#42
UI componentsmodels116142.5%#57
Websitesmodels116744.6%#62

Head-to-head preference voting. How we filter and rank

Supported parameters

  • include_reasoning
  • max_completion_tokens
  • max_tokens
  • reasoning
  • response_format
  • seed
  • structured_outputs
  • tool_choice
  • tools

Call it

OpenAI-compatible: point your SDK at api.openkey.ai/v1 and use model openai/gpt-5-mini.

Code sample language
curl https://api.openkey.ai/v1/chat/completions \
  -H "Authorization: Bearer $OPENKEY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/gpt-5-mini",
    "messages": [{"role": "user", "content": "Hello"}]
  }'
import os
from openai import OpenAI

client = OpenAI(
    base_url="https://api.openkey.ai/v1",
    api_key=os.environ["OPENKEY_API_KEY"],
)

completion = client.chat.completions.create(
    model="openai/gpt-5-mini",
    messages=[{"role": "user", "content": "Hello"}],
)
print(completion.choices[0].message.content)
import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.openkey.ai/v1",
  apiKey: process.env.OPENKEY_API_KEY,
});

const completion = await client.chat.completions.create({
  model: "openai/gpt-5-mini",
  messages: [{ role: "user", content: "Hello" }],
});
console.log(completion.choices[0].message.content);

Questions

How much does GPT-5 Mini cost via API?
Through OpenKey, GPT-5 Mini costs $0.258 per 1M input tokens and $2.06 per 1M output tokens. That is the provider price ($0.250 / $2.00) plus a flat 3% fee — nothing else.
What is GPT-5 Mini's context window?
GPT-5 Mini accepts up to 400K tokens of context and returns up to 128K tokens per request.
Is GPT-5 Mini OpenAI-compatible?
Yes. Send requests to OpenKey's /v1/chat/completions endpoint with model "openai/gpt-5-mini" using any OpenAI SDK — only the base URL and API key change.
What inputs does GPT-5 Mini support?
GPT-5 Mini accepts text, image, file input and produces text output. Its knowledge cutoff is May 31, 2024.

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