Is This ChatGPT's Biggest Free Upgrade Yet?

Unlimited Text Chats Come to ChatGPT Free Tier

OpenAI is making one of its most significant moves yet for users on its free plan. The company announced on August 6, 2026 that GPT-5.6 Luna will become the default model for Free and Go users, with unlimited text chats rolling out as part of the update. It marks the first time OpenAI has removed text message limits for free accounts.

The rollout is staggered. GPT-5.6 Luna becomes the default model for Free and Go users this week, with unlimited text chats and a new Think button arriving the following week. The Think button allows Luna to spend more time working through harder questions on a per-message basis, giving free users a degree of on-demand reasoning they did not previously have.

It is worth noting that the unlimited access has boundaries. File uploads, image generation, and other tools will continue to carry limits on free accounts, meaning the upgrade applies specifically to text conversations.

OpenAI describes Luna as a fast and affordable model within the GPT-5.6 series, which also includes Terra, a balanced everyday model, and Sol, the flagship. The company says it reaches 1 billion users each week across ChatGPT.

Paid Users Receive an Upgraded GPT-5.6 Sol

For Plus and Pro subscribers, OpenAI is shipping an updated version of GPT-5.6 Sol alongside a new reasoning slider. The slider lets paid users decide how much thought ChatGPT applies before answering, from quick everyday replies up to extended effort for planning, research, coding, and complex decisions.

OpenAI says the Sol update focuses on reliability and directness. The model is tuned to avoid unnecessary formatting, keep recommendations clear during longer conversations, and push back when simple agreement would not actually help the user. In internal evaluations covering financial, medical, and legal prompts, OpenAI reported that responses containing at least one factual error fell roughly 62 percent for Luna and 68 percent for Sol compared with GPT-5.5 Instant, the model Luna replaces as the free default. Those figures come from OpenAI's own testing and have not been independently verified.

The update also brings ChatGPT's Instant and Thinking experiences closer together, with both modes now designed to maintain a consistent tone while adjusting only the depth of reasoning based on user settings.

Sources
OpenAI: Improving GPT-5.6 Sol in ChatGPT and expanding access to GPT-5.6 Luna for free users
The Decoder: OpenAI improves GPT-5.6 Sol and restricts free users to its weakest model
OpenAI: Previewing GPT-5.6 Sol, a next-generation model