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OpenKey

GPT-5

OpenAIReleased Aug 7, 2025

GPT-5 is OpenAI’s most advanced model, offering major improvements in reasoning, code quality, and user experience. It is optimized for complex tasks that require step-by-step reasoning, instruction following, and accuracy...

Try in playground
Context window
400K tokens
Max output
128K tokens
Input
text, image, file
Output
text
Tokenizer
GPT
Knowledge cutoff
Sep 30, 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$1.25$0.037$1.29
Output$10.00$0.300$10.30
Cache read$0.125$0.0037$0.129

Benchmarks

Design Arena

CategoryEloWin rateRank
3Dmodels113341.4%#68
ASCII artmodels118849%#29
Codemodels121854.7%#43
Data vizmodels128263.3%#15
Game devmodels125259.5%#31
SVGmodels124664.1%#14
UI componentsmodels123858.3%#33
Websitesmodels122753.7%#42

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.

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",
    "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",
    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",
  messages: [{ role: "user", content: "Hello" }],
});
console.log(completion.choices[0].message.content);

Questions

How much does GPT-5 cost via API?
Through OpenKey, GPT-5 costs $1.29 per 1M input tokens and $10.30 per 1M output tokens. That is the provider price ($1.25 / $10.00) plus a flat 3% fee — nothing else.
What is GPT-5's context window?
GPT-5 accepts up to 400K tokens of context and returns up to 128K tokens per request.
Is GPT-5 OpenAI-compatible?
Yes. Send requests to OpenKey's /v1/chat/completions endpoint with model "openai/gpt-5" using any OpenAI SDK — only the base URL and API key change.
What inputs does GPT-5 support?
GPT-5 accepts text, image, file input and produces text output. Its knowledge cutoff is Sep 30, 2024.

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