OpenAI launched GPT-5.6 on July 9, 2026, rolling out its most capable model family to the public after additional government testing. The release comes in three variants: Sol, Terra, and Luna, each targeting different use cases and price points.
Three Tiers, Different Strengths
GPT-5.6 Sol is the flagship. It leads on reasoning, coding, science, and instruction-following benchmarks. Priced at $5 input and $30 output per million tokens, it targets developers and enterprises that need maximum capability.
GPT-5.6 Terra is positioned as the balanced everyday model. OpenAI describes it as competitive with GPT-5.5 performance at roughly half the cost. Pricing: $2.50 input and $15 output per million tokens.
GPT-5.6 Luna is the speed-optimized option. It runs at up to 750 tokens per second on Cerebras infrastructure and costs just $1 input and $6 output per million tokens. For high-volume applications where latency matters more than peak reasoning, Luna makes a strong case.
Batch and Caching Discounts
All three tiers support batch processing and prompt caching, which can cut costs by 50% to 90% depending on the use case. Terra with batch pricing drops to $1.25 input and $7.50 output per million tokens, making it one of the cheapest models available at its capability level.
ChatGPT Work Agent
Alongside the model release, OpenAI shipped ChatGPT Work, an agent built to handle autonomous tasks across business workflows. The agent can browse the web, analyze documents, and execute multi-step processes without constant human oversight. It’s available to ChatGPT Pro and Enterprise subscribers.
Availability and Access
GPT-5.6 Sol, Terra, and Luna are accessible through the OpenAI API, ChatGPT, and Azure OpenAI Service. The rollout started globally on July 9 and should reach full availability within 24 hours. Free-tier ChatGPT users get access to Luna, while Pro subscribers can use all three tiers.
OpenAI also confirmed that OCR capabilities are coming to GPT-5.6 in a future update, which would expand its utility for document processing and data extraction tasks.
Frequently Asked Questions
What are the differences between GPT-5.6 Sol, Terra, and Luna?
Sol is the most capable model for reasoning and coding. Terra is a balanced mid-tier model at half the cost of Sol. Luna is the fastest and cheapest, optimized for speed and high-volume tasks.
How much does GPT-5.6 cost per million tokens?
Sol: $5 input / $30 output. Terra: $2.50 input / $15 output. Luna: $1 input / $6 output. Batch pricing and caching discounts can reduce these costs further.
Can free ChatGPT users access GPT-5.6?
Free-tier users get access to GPT-5.6 Luna. Pro and Enterprise subscribers can use all three tiers including Sol.
When will GPT-5.6 be fully available?
OpenAI began the global rollout on July 9, 2026 and stated it would reach full availability within 24 hours of the announcement.
What is ChatGPT Work?
ChatGPT Work is a new agent from OpenAI that handles autonomous tasks including web browsing, document analysis, and multi-step business workflows. It’s available to Pro and Enterprise subscribers.
