OpenAI has updated ChatGPT, rolling out GPT-5.6 Luna to free users and GPT-5.6 Sol to paid users, along with a new thinking intensity slider. The new models show improved factual reliability, and free users get unlimited text conversations, though with usage limits.
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OpenAI upgrades the default model for free users to GPT-5.6 Luna, offering unlimited text conversations; paid users get GPT-5.6 Sol with a new thinking intensity slider. Internal evaluations show a significant reduction in factual errors, but anti-abuse limits and tool restrictions remain.
OpenAI has updated ChatGPT, and the default model for free and Go users will be upgraded to GPT-5.6 Luna, unlocking unlimited text conversations. However, unlimited text conversations are still subject to anti-abuse mechanisms, and restrictions on file uploads, images, and other tools remain unchanged.
Plus and Pro users get the updated GPT-5.6 Sol starting today, which provides more focused answers and improved factual reliability. The same model handles both instant answers and deep reasoning, avoiding abrupt style changes when users switch between different thinking intensities.
A new thinking intensity slider is added to ChatGPT's web, mobile, and desktop interfaces, allowing users to decide how much effort the model puts into each response. For everyday questions, users can choose quick answers; for planning, research, writing, coding, or tasks requiring careful judgment, they can increase the thinking intensity.
For simple questions, GPT-5.6 Sol prioritizes direct answers with necessary context; for complex tasks, it provides more complete responses while keeping core recommendations clear.
OpenAI's internal evaluations show that compared to GPT-5.5 Instant, the incidence of answers containing at least one factual error is reduced by about 62% for GPT-5.6 Luna and about 68% for GPT-5.6 Sol. The evaluations cover financial, medical, and legal questions that require specific factual support.
The new GPT-5.6 Sol will better utilize search and retrieved source information, particularly reducing factual errors in questions involving dates, numbers, sources, rules, and assumptions.
The updated GPT-5.6 Sol is specifically optimized for everyday ChatGPT conversations and is only available in the ChatGPT Chat experience. The GPT-5.6 Sol version powering ChatGPT Work and Codex will not change with this release.
OpenAI states that 1 billion people use ChatGPT weekly for various tasks. This adjustment aims to bring instant answers and deep thinking closer together, maintaining consistency in tone and behavior.
This report is based on AI Front's transcription of OpenAI's official announcement, without providing original official links or independent verification. The internal evaluation data is solely claimed by OpenAI, and specific testing methods have not been disclosed; it should be regarded as a source claim rather than independent confirmation.
OpenAI is democratizing advanced reasoning capabilities by offering free upgrades and a thinking slider, while emphasizing improved factual reliability. However, anti-abuse and tool restrictions remain, and actual user experience needs to be verified by users themselves.
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