OpenAI on Thursday announced a series of changes that will upgrade ChatGPT for both paid and free users.

Why it matters: Free AI plans from frontier labs now offer more intelligence than most people will use, while enterprises are still figuring out how to budget for advanced capabilities.

Driving the news: OpenAI said it will shift the default model for all users to GPT-5.6 Luna this week.

OpenAI says that responses featuring at least one factual error were 62% less common with Luna opposed to the previous default model, GPT‑5.5 Instant. Luna, which debuted in early July, was built for speed.
Unlimited text chats will be given to free users and those who subscribe to the low-cost Go plan. Both free and go users will also see a new "Think" button, which lets users "select higher reasoning for harder questions," the company says.

Plus and Pro users will see GPT-5.6 Sol improved to handle "everyday conversations and tasks, like quick questions, web research, advice, planning, writing, and decisions," OpenAI says.

"This version of GPT-5.6 Sol delivers more focused answers," the company said, with less unnecessary formatting, a consistent tone and fewer mistakes.

It will also feature a new "slider" tool "for choosing how much thought ChatGPT puts into an answer," OpenAI says.

The big picture: Cheaper Chinese open-weight models have increased pressure on OpenAI and Anthropic to prove their models justify the higher costs.

OpenAI recently cut the prices for two of its GPT-5.6 models — GPT-5.6 Luna and GPT-5.6 Terra — last week.
Price cuts have previously come months after a model launches, not weeks.