OpenAI Makes GPT-5.6 Sol ChatGPT Default, Tops GPQA Diamond at 94.6%
Updated
Updated · tech-insider.org · Jul 19
OpenAI Makes GPT-5.6 Sol ChatGPT Default, Tops GPQA Diamond at 94.6%
3 articles · Updated · tech-insider.org · Jul 19
Summary
July 9 marked OpenAI’s rollout of GPT-5.6 Sol as ChatGPT’s new default, replacing GPT-5.5 and positioning the model as its flagship for everyday use and frontier reasoning.
94.6% on GPQA Diamond put Sol atop a benchmark widely treated as a hard test of expert-level reasoning; its “max” setup also scored 59 on Artificial Analysis’ intelligence index, ahead of Claude Opus 4.8’s 55.7.
$5 per million input tokens and $30 per million output tokens make Sol the priciest of the three leading models on output, though OpenAI also offers lower-tier Terra and Luna options for cheaper workloads.
The launch lands in a crowded 2026 race: Anthropic’s Opus 4.8 leads documented agentic-coding tests, while Google’s Gemini 3.1 Pro offers broader multimodal input and lower estimated pricing but remains in public preview.
With all three models now clustered around 1 million tokens of context, buyers are increasingly choosing by reasoning scores, coding reliability and cost rather than context-window size alone.
As hidden 'thinking tokens' silently inflate AI costs, is the race for peak reasoning performance becoming financially unsustainable for enterprises?
Beyond the model wars, who is winning the silent battle to become the essential operating system for enterprise AI agents?
With US export controls disabling AI models overnight, how can businesses build a truly resilient and future-proof AI strategy?
GPT-5.6 Sol and Family: OpenAI’s 2026 Models Redefine AI Performance, Security, and Affordability
Overview
On July 9, 2026, OpenAI launched the GPT-5.6 family, introducing three new models—Sol, Terra, and Luna—to expand its presence in the competitive AI landscape. Each model is designed for different performance and efficiency needs, making advanced intelligence more accessible and affordable for a wide range of applications. The GPT-5.6 family stands out for its focus on efficiency and enhanced performance, especially in its smaller models. Notably, Terra and Luna outperform a key competitor at a fraction of the cost, highlighting OpenAI’s commitment to delivering powerful yet economical AI solutions.