GPT-5.6 Sol nearly matches Fable 5 on aggregated benchmarks at one-third the cost

OpenAI has released its GPT-5.6 model series, featuring the high-end Sol variant which achieves performance nearly identical to Anthropic's Claude Fable 5 on aggregated benchmarks. Sol particularly excels in agentic coding tasks, where it currently leads the industry. By offering this capability at one-third the cost of competing top-tier models, OpenAI is significantly increasing pricing pressure within the AI sector. The series is now available in three distinct tiers, marking a shift toward more granular model options for developers.