GPT-5.4 reportedly brings a million-token context window and an extreme reasoning mode

OpenAI's GPT-5.4 could be the leap forward that the just-released 5.3 Instant for ChatGPT wasn't. The model should drop "sooner than you think," according to OpenAI, but no official details have been shared yet.

According to The Information, GPT-5.4 will feature a one-million-token context window, more than double the 400,000 tokens in the current GPT-5.2. That would put OpenAI on par with Google and Anthropic. The model is also expected to be more reliable and make fewer mistakes on longer tasks that can run for several hours, which matters especially for tools like OpenAI's Codex programming agent.

One notable addition is an "extreme" thinking mode that lets the model burn significantly more compute on tough questions. This mode is aimed at researchers rather than everyday users who want quick answers. According to The Information, the more frequent model release cadence is designed to keep expectations in check. The hype around the GPT-5 launch set the bar so high it was nearly impossible to clear, and OpenAI's user growth has recently fallen short of internal projections.