The context window size in ChatGPT varies depending on the subscription level and the specific model in use.

ChatGPT Plus Subscription:

- Users with a ChatGPT Plus subscription have access to GPT-4, which offers a context window of up to 8,192 tokens.

ChatGPT Pro Subscription: - The ChatGPT Pro subscription provides access to GPT-4 Turbo, featuring a significantly larger context window of up to 128,000 tokens.

This expanded context window in the Pro version allows for more extensive and coherent interactions, accommodating longer conversations and more complex queries.

GPT-4 context window sizes vary based on subscription plans as of December 2024:

• ChatGPT Free Tier: Uses GPT-3.5 with a context window of 4,096 tokens.

• ChatGPT Plus Subscription: Provides access to GPT-4o with a context window of 32K tokens.

• ChatGPT Pro Subscription: Offers advanced models, including GPT-4o and o1, supporting expanded context windows of 128K. https://openai.com/index/introducing-chatgpt-pro

• ChatGPT Enterprise: Includes access to GPT-4 Turbo with a context window of 128,000 tokens for enterprise-scale tasks.

https://openai.com/chatgpt/pricing