tech
Previewing GPT-5.6 Sol: a next-generation model
We're beginning a limited preview of the GPT‑5.6 series: Sol, our flagship model; Terra, a balanced model for everyday work; and Luna, a fast and affordable model. Terra has competitive performance to GPT‑5.5 while being 2x cheaper and Luna brings strong capability at our lowest cost.
TL;DR
- OpenAI introduces GPT-5.6 series: Sol (flagship), Terra (balanced), and Luna (fast, affordable).
- Terra offers competitive performance to GPT-5.5 at half the cost; Luna is the most affordable.
- GPT-5.6 Sol boasts enhanced agentic capabilities in coding, biology, and cybersecurity with strengthened safety measures.
- New features include 'max' reasoning effort for Sol and 'ultra' mode leveraging subagents for complex tasks.
- The models are undergoing a phased, limited preview with trusted partners before general availability.
- Safety is a priority, with layered safeguards to protect against misuse while enabling legitimate defensive work.
- Automated and human red-teaming were used extensively to test and improve safeguards.
- GPT-5.6 Sol is positioned to assist in vulnerability finding and fixing rather than carrying out attacks.
- Pricing is per 1M tokens: Sol ($5 input / $30 output), Terra ($2.50 input / $15 output), Luna ($1 input / $6 output).
- GPT-5.6 Sol will also be available on Cerebras at up to 750 tokens per second in July.