The GPT-5 launch comes as OpenAI faces increasing competition from Google's Gemini models, Anthropic's Claude family, and Meta's open-weight Llama models. OpenAI reports having 5 million paying business users and 4 million developers building on its API platform.

In addition to architectural changes, OpenAI opted not to increase GPT-5's context window, which you can think of as its long-term memory. Free users are still limited to an 8,000-token context while Plus and Pro users cap out at 128,000 tokens.