Last refreshed 2026-05-20. Next refresh: weekly.
Why use GPT-4.5 on OpenAI API?
OpenAI API offers GPT-4.5 with competitive pricing. OpenAI is a leading AI research and deployment company dedicated to developing safe and beneficial artificial general intelligence (AGI) for humanity.
Compare GPT-4.5 across 2 providers to find the best fit for your use caseInput / 1M
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Output / 1M
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Cache
Not sourced
Batch
Not sourced
Setup recipe
Python + curlInstall
pip install openaiAuth
export OPENAI_API_KEY=...Call
import os
from openai import OpenAI
client = OpenAI() # reads OPENAI_API_KEY from env
response = client.chat.completions.create(Model ID
gpt-4-5Request example
import os
from openai import OpenAI
client = OpenAI() # reads OPENAI_API_KEY from env
response = client.chat.completions.create(
model="gpt-4-5",
messages=[{"role": "user", "content": "Hello"}]
)
print(response.choices[0].message.content)Gotchas
- Use the model slug directly, e.g. "gpt-4o" or "gpt-4.1-mini".
- The examples expect OPENAI_API_KEY; rename it only if your application config maps the new variable.
Compare GPT-4.5 Across Providers
| Provider | Input (per 1M) | Output (per 1M) |
|---|---|---|
| OpenAI API | — | — |
| Azure OpenAI | — | — |
Capabilities
VisionMultimodalFunction CallingTool UseStructured OutputsCode Execution
About GPT-4.5
Improved GPT-4 variant released March 2026. Enhanced performance over GPT-4o with better reasoning and code generation.
FAQ
What is the context window for GPT-4.5 on OpenAI API?
GPT-4.5 supports a 8,000 token context window on OpenAI API.
Who created GPT-4.5?
GPT-4.5 was created by OpenAI as part of the GPT-4.5 model family.
Is GPT-4.5 open source?
GPT-4.5 is not open source; the seed data lists it as proprietary.
Get Started
Model Specs
Released2025-02-27
Context8K
Knowledge cutoff2025-04