Leaks began circulating Thursday, September 24, when TestingCatalog found references to a new "Pro Max" tier buried in OpenAI's backend. Independent researcher Tibor Blaho spotted the same strings, and the AI leaks account Chetaslua posted screenshots of the tier inside ChatGPT's own subscription interface. OpenAI has not confirmed any of it.

The headline feature is "Fastest Work and Codex" — raw speed for OpenAI's long-running agent products, Work and Codex, rather than more usage. The tier also advertises maximum memory, 100GB of file storage, early feature access, and priority availability for the most capable frontier models. The price: $500 a month in the US, 25 times ChatGPT Plus and 2.5 times the $200 Pro plan, with $100 Pro 5x and $200 Pro 20x tiers alongside it in the leaked configs.

An independent check on September 25 queried ChatGPT's own checkout pricing configs for 14 countries and found a promax entry in every one, at five times the Pro 5x price in each market. On September 26 a Reddit thread on r/ChatGPT independently confirmed the $500 pricing, with code identifiers for "chatgptpromax" matching what the leakers found. Press speculation links the speed to Cerebras hardware, which already powers OpenAI's fastest Codex modes. The timing points at DevDay on September 29, where OpenAI typically unveils pricing news — and the company paused new $200 Pro sign-ups in mid-September under demand strain from GPT-6 Astra.