GPT-5.6 overview
GPT-5.6 by OpenAI
GPT-5.6 launched on July 9, 2026 following a limited preview that began June 26, 2026.
GPT-5.6 specs
- Developer
- OpenAI
- Input
- Text
- Output
- Text
- API
- OpenAI-compatible, base URL
https://api.aimlapi.com/v1
What Is GPT-5.6?
GPT-5.6 is OpenAI's model family, first previewed on June 26, 2026 to a limited group of trusted partners, then released generally on July 9, 2026. It ships in three tiers: Sol (the flagship), Terra (a balanced mid-tier model), and Luna (the most cost-efficient tier). Each tier is also available in a Pro configuration that runs the same underlying model with reasoning mode set to pro for harder tasks.
OpenAI describes GPT-5.6 as bringing stronger capabilities in coding, scientific research, and cybersecurity, calling Sol its "strongest cybersecurity model yet." The company reported Sol is roughly 54% more token-efficient on AI coding tasks compared to GPT-5.5.
The Three Tiers
Sol
OpenAI's flagship GPT-5.6 model, built for the deepest reasoning on software engineering, research, and agentic work.
Terra
A balanced tier for everyday coding and agentic work at roughly half the cost of Sol.
Luna
The fastest and most cost-efficient tier, built for high-volume, latency-sensitive workloads.
Explore the GPT-5.6 Models
Each tier and its Pro configuration has its own API page with full pricing, technical specs, and code samples: GPT-5.6 Sol, GPT-5.6 Sol Pro, GPT-5.6 Terra, GPT-5.6 Terra Pro, GPT-5.6 Luna, and GPT-5.6 Luna Pro.
Sources: https://openai.com/index/gpt-5-6/ · https://openai.com/index/previewing-gpt-5-6-sol/ · https://en.wikipedia.org/wiki/GPT-5.6
Use cases
GPT-5.6 is documented as suitable for programming, knowledge work, cybersecurity, and science.
It is also documented for defensive cybersecurity tasks, including secure code review, patching, threat modeling, and blue teaming.
OpenAI also describes it as useful for complex work across coding, knowledge work, research, cybersecurity, science, computer use, and design.
For builders, it is presented as a strong fit for high-volume workloads, latency-sensitive interactions, and repeated steps within agentic workflows.
Capabilities
- Function calling
- Streaming
- Structured outputs
Models similar to GPT-5.6
GPT-5.6 FAQ
When was GPT-5.6 released?
GPT-5.6 became available on July 9, 2026.
Does GPT-5.6 support streaming?
Yes, GPT-5.6 can stream responses as they are generated.
Does GPT-5.6 support tool calling and structured outputs?
Yes, GPT-5.6 supports both function calling and structured outputs.
Who created GPT-5.6?
GPT-5.6 was built by OpenAI.