ChatGPT Free Tier Gets Epic Upgrade: GPT-5.6 Unlimited Access

OpenAI announced an upgrade for ChatGPT's free tier, making GPT-5.6 Luna the default model with unlimited chat usage, rolling out this week. Plus and Pro users receive a specialized upgrade for GPT-5.6 Sol in Chat mode, improving factual accuracy and response quality, though this update is only for the ChatGPT chat experience, not for Work or Codex. The upgrade addresses the needs of the 1 billion weekly users who use ChatGPT for quick Q&A, web search, planning, research, and consultation. In internal evaluations for financial, medical, and legal prompts, GPT-5.6 Luna showed about 62% fewer factually erroneous responses compared to GPT-5.5 Instant, and GPT-5.6 Sol about 68% fewer. Plus and Pro users also get a new UI feature allowing them to adjust the reasoning effort via a slider on web, mobile, and desktop. Free users retain limits on image generation and file uploads but get a new thinking button for complex queries. The article also mentions comments by ByteDance founder Zhang Yiming at a Seed meeting, who said that programming is just a current hot spot and should not dominate all attention, encouraging the Seed team to pursue higher intelligence limits.