GPT-5 makes reasoning the default (2025)
On August 7, 2025, OpenAI releases GPT-5 as a unified system that decides when to answer quickly and when to think longer, and ships it to every ChatGPT user; a bumpy rollout shows how attached people have become to individual models.
On August 7, 2025, two and a half years after GPT-4, OpenAI released GPT-5, calling it its best system yet. The launch was watched as a test of whether generative AI was still accelerating or hitting a plateau. For the GPT line that began with ChatGPT, it was the first new numbered flagship since March 2023.
One system instead of a model menu
GPT-5 was pitched as a single stack: a fast large language model, a deeper reasoning model (“GPT-5 thinking”), and a real-time model router that picks which to use based on conversation type, complexity, tool needs, and explicit intent (for example, “think hard about this”). When users hit limits, a mini variant takes over. OpenAI said it eventually wants those capabilities in one model. Training ran on Microsoft Azure supercomputers.
The same day, GPT-5 replaced the manual picker in ChatGPT. Free, Plus, Pro, and Team users received access immediately; Enterprise and Edu followed a week later. The API launched alongside the consumer rollout.
Reasoning for everyone
o1 had introduced “think first, then answer” as a specialist mode you paid extra for. With GPT-5, OpenAI brought that behaviour into the default experience. CNBC noted that free users gained access to a reasoning model for the first time, with the router deciding how much deliberation to spend.
OpenAI said nearly 700 million people were using ChatGPT weekly at launch. That scale matters: inference time reasoning was no longer a lab demo but a product path for hundreds of millions of users.
OpenAI also published benchmark figures as its own claims, including 94.6% on AIME 2025 without tools, 74.9% on SWE-bench Verified, and lower reported error rates than GPT-4o or o3 when web search or thinking modes were enabled. Independent reviewers treated the release more as polished product than scientific leap; AP quoted CEO Sam Altman calling GPT-5 a “significant step along our path to AGI.”
The backlash over GPT-4o
The rollout was rough. Removing GPT-4o from the model menu angered users who had built workflows and emotional attachments around that voice. The Verge and Wired reported shorter, cooler answers and mourning in communities such as r/MyBoyfriendIsAI, a thread that reaches back to ELIZA.
On August 8, Altman said OpenAI would let Plus users choose to keep using GPT-4o and promised higher limits and more transparency about which model was answering. The episode became an early, well-documented case of people bonding with chatbots as companions, not just tools.
Why it matters
After the Stargate spending announcements and the DeepSeek shock, GPT-5 was billed as proof that frontier labs could still ship. The numbers suggested gains in coding, maths, and fewer hallucinations, but the louder story was product design: reasoning by default, routing hidden from the user, and a revolt when a familiar model disappeared.
Whether GPT-5 was a research breakthrough or a better router around existing skills is still debated. What is clear is that the industry bet on unified assistants where the machine decides how long to think, and that users noticed when the choice was taken away.