OpenAI previews GPT-5.6-sol reasoning model for Pro and Enterprise users
OpenAI has opened preview access to GPT-5.6-sol, a reasoning-focused model variant designed for complex problem-solving tasks.
OpenAI previewed GPT-5.6-sol this week, a new model variant built for extended reasoning workflows. The "sol" designation signals a solver-oriented design, similar to the o1 and o3 reasoning models OpenAI shipped earlier this year. Unlike standard GPT models that generate responses in a single forward pass, GPT-5.6-sol allocates compute budget to internal reasoning tokens before producing a final answer. Preview access is available through the OpenAI API and ChatGPT interface for users on Pro and Enterprise tiers.
OpenAI's announcement describes the model as optimized for mathematics, coding, and multi-step logical tasks where showing work improves accuracy. The timing puts GPT-5.6-sol in direct competition with Anthropic's Claude 3.7 Opus and Google's Gemini 2.0 Pro, both of which added extended-thinking modes in the past quarter. OpenAI has not disclosed whether GPT-5.6-sol shares architecture with the GPT-5 base model rumored for later this year, or if it represents a separate reasoning-specific training run. The company also did not publish benchmark scores, context window size, or token pricing in the initial preview announcement.
The release underscores the widening gap between closed API reasoning models and open-weight alternatives. DeepSeek-R1, Qwen-QwQ, and abliterated Llama variants have all demonstrated competitive reasoning performance on consumer hardware in recent months, while OpenAI's reasoning lineup remains API-only and safety-tuned. GPT-5.6-sol preview access is live now for eligible tier subscribers.
