GPT-5.6 Terra Pro

• 🏢 OpenAI's GPT-5.6 Terra, served with reasoning mode set to Pro.
• 🆕 Part of the GPT-5.6 Sol/Terra/Luna tiered lineup.
• 📏 Handles up to a 1,000,000-token context window.
• 🧠 Extended compute for higher-quality responses on complex tasks.
• 👁️ Supports vision, function calling, and built-in web search.
• 🎯 Reasoning effort scales the quality of Pro-mode responses.
• 📚 A higher pricing tier applies above 272K input tokens.

OpenAI

OpenAI is an American artificial intelligence research organization headquartered in San Francisco, structured as both a for-profit public benefit corporation and a nonprofit foundation. The lab developed the GPT family of large language models, the DALL-E…

GPT-5.6 Terra Pro, released in July 2026, is the Pro-served variant of GPT-5.6 Terra, OpenAI's balanced mid-tier model. Per the catalog description, it is the same underlying model as Terra but run with reasoning mode set to Pro, using more compute to produce higher-quality answers on complex tasks. It carries a one-million-token context window and supports reasoning, vision, function calling, and web search.

Within the GPT-5.6 family, OpenAI uses a tiered naming scheme where the number denotes the generation and the name denotes the capability tier: GPT-5.6 Sol, GPT-5.6 Terra, and GPT-5.6 Luna. The Pro layer adds an extended-compute option to each tier, much as GPT-5.6 Sol Pro and GPT-5.6 Luna Pro do for theirs.

Compared with the earlier-generation GPT-5.5 Pro, the Pro concept is consistent — spending more inference compute to think harder for more reliable answers. OpenAI's Terra model documentation notes tiered pricing in which prompts above 272K input tokens are billed at higher rates.

OpenAI has not published detailed public benchmark figures for the Pro runs, so quantitative comparisons against predecessors remain limited from primary sources.