SAN FRANCISCO, CALIFORNIA / RankWire.AI / – OpenAI is expanding access to ChatGPT by offering Free and Go users unlimited text conversations with GPT-5.6 Luna. The company announced that this change will take effect next week and will be subject to safeguards against misuse. During the current rollout, GPT-5.6 Luna will also become the default model for those accounts. Additionally, free users will now have a Think button, enabling the system to dedicate more time to complex questions before responding.
This new access permits unlimited text chats but does not eliminate all usage restrictions across ChatGPT. OpenAI clarified that limits will still apply to file uploads, image generation, and other tools requiring extra processing. The Think feature will be introduced alongside unlimited messaging next week, allowing GPT-5.6 Luna to allocate more reasoning time for tasks that demand deeper analysis. The company maintains separate controls for features outside of standard text conversations, including tools available under different usage allowances.
OpenAI unveiled GPT-5.6 as a collection of models, comprising Luna, Sol, and Terra. Luna is designed as the faster and more cost-effective option within this lineup. The company stated that ChatGPT currently serves approximately one billion weekly users across searches, research, planning, writing, and other activities. With this latest update, Luna will be the primary ChatGPT model for users on Free and Go plans. The expansion provides broader access to the core chat service, while maintaining limits on specific tools.
Updated reasoning model available to paid subscribers
Subscribers of ChatGPT Plus and Pro will also receive an upgraded version of GPT-5.6 Sol for daily use. Sol supports both quick replies and more in-depth reasoning within the paid experience. OpenAI explained that this update results in more targeted responses and minimizes unnecessary details when a simpler answer suffices. Paid users will also gain a reasoning slider across web, mobile, and desktop platforms, which allows them to control how much processing ChatGPT applies to tasks such as research, planning, coding, and writing.
The company further reported a decrease in factual inaccuracies during internal testing of its latest models, especially in responses involving financial, medical, and legal prompts requiring precise factual information. OpenAI noted that responses containing at least one factual error dropped by roughly 62% with GPT-5.6 Luna compared to GPT-5.5 Instant. For GPT-5.6 Sol, errors decreased by about 68%. The company also highlighted improvements in Sol’s ability to handle dates, numbers, sources, rules, and assumptions when these details are critical to an answer.
Unlimited messaging continues with safety measures in place
OpenAI stated that its latest ChatGPT models feature enhanced protections for users believed to be under 18. These safeguards aim to prevent romantic roleplay, age-restricted challenges, and claims that could replace real-world relationships. Boundaries regarding sexual content, eating disorders, dangerous activities, restricted substances, and graphic violence are also enforced. The company mentioned that it has introduced new assessments for responses involving younger users. Unlimited text conversations will still operate within the same safeguards once expanded access is available to Free and Go accounts.
This update focuses on the core ChatGPT experience rather than every OpenAI product utilizing GPT-5.6 models. According to the company, GPT-5.6 Sol versions used in ChatGPT Work and Codex will not change with this release. Paid users can now access the updated Sol model and reasoning controls, while Free and Go users will have Luna as their default model starting this week. Unlimited messaging and the Think button will become available next week, with separate restrictions remaining for images, uploads, and other tools.