OpenAI
GPT-5.6 Luna
GPT-5.6 Luna is an AI model released by OpenAI on Friday, Jun 26 2026, the same day as GPT-5.6 Terra. Benchmark results (shown below) cover BullshitBench v2, and Terminal-Bench 2.1.
Benchmarks
Nonsense detection
BullshitBench v2Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better.
40%-13%vs GPT-5.6 Terra
Agentic terminal coding
Terminal-Bench 2.1Can the AI work in a command-line terminal — running commands and finishing technical setup tasks the way a developer would? Higher is better.
82.5%-1.8%vs GPT-5.6 Terra