OpenAI Officially Announces GPT-5.6 Full Launch This Thursday, Three Tiers Named After Celestial Bodies

OpenAI has officially announced that the GPT-5.6 series models will be fully launched to the public this Thursday. The release has been approved by the U.S. Department of Commerce's AI Standards and Innovation Center (CAISI), with OpenAI sending technical experts to Washington for review.

Model Tiers and Pricing

The GPT-5.6 series includes three tiers named after celestial bodies:

• Sol (Sun): Flagship model, priced at $5 per million input tokens and $30 per million output tokens.
• Terra (Earth) and Luna (Moon): Mid-range and entry-level, with pricing yet to be announced.

Initial Beta Performance

NVIDIA's chief engineer tested Sol and found it outperformed Opus's 64-hour CUDA acceleration in 30 hours. User feedback consensus includes:

• Cleaner code: Sol's code lines are only 1/5 of Opus's, especially C++ code resembling human-written style with fewer comments.
• Deep optimization: The model abandons extensive trial-and-error, focusing on underlying performance optimization, but iteration is slower with more failures.
• Vision and reasoning: In tasks like interactive SVG, 3D models, and game generation, Sol shows better instruction following and spatial reasoning than GPT-5.5 Pro.

Comparison with Competitor Fable 5

• Cost advantage: Sol's input/output cost ($5/$30 per million tokens) is half of Fable 5 ($10/$50).
• Capability gap: Sol matches or surpasses Fable 5 in some benchmarks, but overall model experience and code quality are slightly inferior. For example, Fable 5 can convert a prompt into a playable 3D FPS game, while Sol is still adapting.
• Safety restrictions: Fable 5 faces strict security reviews due to sanctions, often blocking normal tasks; GPT-5.6 officially states it has added stronger safety systems with fewer restrictions.

Launch Expectations

OpenAI CEO Sam Altman compared GPT-5.6's discovery of new mathematical theories to "a child saying their first two-word phrase." The model was previously hinted at in Codex CLI 0.143.0, with new support for Amazon Bedrock. After full launch, all users can access it, no longer limited to partners.