How to Beginner · 3 min read

GPT-4o context window size

Q: GPT-4o context window size

The gpt-4o model supports a context window size of 8,192 tokens, allowing it to process long conversations or documents in a single request. Use this large context window to provide extensive context or multi-turn dialogue history when calling client.chat.completions.create.

Quick answer

The gpt-4o model supports a context window size of 8,192 tokens, allowing it to process long conversations or documents in a single request. Use this large context window to provide extensive context or multi-turn dialogue history when calling client.chat.completions.create.

PREREQUISITES

Python 3.8+
OpenAI API key (free tier works)
pip install openai>=1.0

Setup

Install the official OpenAI Python SDK and set your API key as an environment variable to access gpt-4o.

bash

pip install openai>=1.0

output

Collecting openai
  Downloading openai-1.x.x-py3-none-any.whl
Installing collected packages: openai
Successfully installed openai-1.x.x

Step by step

This example demonstrates how to send a prompt to gpt-4o using the OpenAI SDK v1 and handle the large context window.

python

import os
from openai import OpenAI

client = OpenAI(api_key=os.environ["OPENAI_API_KEY"])

messages = [
    {"role": "system", "content": "You are a helpful assistant."},
    {"role": "user", "content": "Explain the significance of the 8192 token context window in GPT-4o."}
]

response = client.chat.completions.create(
    model="gpt-4o",
    messages=messages,
    max_tokens=512
)

print("Response:", response.choices[0].message.content)

output

Response: The 8192 token context window in gpt-4o allows the model to consider a large amount of text in one go, enabling it to understand and generate responses based on extensive conversations or documents without losing context.

Common variations

You can stream responses from gpt-4o by setting stream=True in the request. Also, smaller context windows apply to models like gpt-4o-mini (2048 tokens).

python

import os
from openai import OpenAI

client = OpenAI(api_key=os.environ["OPENAI_API_KEY"])

messages = [
    {"role": "user", "content": "Stream a response from gpt-4o."}
]

stream = client.chat.completions.create(
    model="gpt-4o",
    messages=messages,
    stream=True
)

for chunk in stream:
    delta = chunk.choices[0].delta.content or ""
    print(delta, end="", flush=True)

output

Streaming response text appears here in real time...

Troubleshooting

If you receive errors about exceeding the context window, reduce the total tokens in your messages and max_tokens combined to under 8192 tokens. Use token counting tools to estimate input size.

✅

Key Takeaways

The gpt-4o model supports an 8,192 token context window for large inputs.
Use the OpenAI SDK v1 client.chat.completions.create method to interact with gpt-4o.
Streaming responses are supported by setting stream=True in the request.
Ensure your total tokens (prompt + completion) do not exceed 8,192 to avoid errors.

Verified 2026-04 · gpt-4o, gpt-4o-mini

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