OpenAI’s GPT-6 Sol doubles its accuracy rate – for half the cost

OpenAI says GPT-6 Sol makes half as many mistakes as GPT-5.6. GPT-6 Luna matches previous higher-tier AI performance at far lower cost. OpenAI’s real pitch is cheaper AI, not just smarter AI. Today, OpenAI is announcing the release and general availability of its new mainstream models, GPT-6 Sol and GPT-6 Luna. While new AI model releases are now a constant drumbeat in the AI industry, the reliability improvements announced today stand out from a sea of statistics. OpenAI says that “GPT-6 Sol makes about half as many mistakes as its predecessor.” The company also says, “GPT-6 Luna also improves substantially; at higher effort levels it matches GPT-5.6 Sol at about a hundredth its cost.” (Disclosure: Ziff Davis, ZDNET’s parent company, filed an April 2025 lawsuit against OpenAI, alleging it infringed Ziff Davis copyrights in training and operating its AI systems.) In other words, if GPT-5.6 was making factual errors 20% of the time, GPT-6 is making them only 10% of the time, based on the same queries. GPT-6 Luna, the low-cost engine, now performs as well as its more capable tier in the previous release. Let’s put these models into some perspective. Both OpenAI and Anthropic have flagship, workhorse,…