Has OpenAI’s GPT-5.6 class beaten Anthropic’s Fable-class models?
OpenAI has officially launched its next-generation GPT-5.6 model family, consisting of three distinct tiers named Sol, Terra, and Luna. The release arrives just one week after Anthropic fully restored access to its competing Fable 5 models for all users.
OpenAI has introduced a new architectural strategy with the release of GPT-5.6, opting for a tiered family of models rather than a single flagship entity. The three tiers—Sol, Terra, and Luna—are priced separately, with Sol representing the high-end capability tier and Luna serving as the entry point.
According to the company, this tiered structure allows each specific model to advance at its own unique tempo based on specific performance targets. This rollout directly follows the recent return of Anthropic's Fable 5 models to the public market, intensifying competition in the high-end AI sector.
While initial comparisons are being drawn between the GPT-5.6 family and the Fable-class models, the staggered capabilities of Sol, Terra, and Luna offer different benchmarks for enterprise and individual use cases. Source: OpenAI.
