ChatGPT 5.6 vs Claude Fable 5: I Tested Both
I tested both on real work. One feels like a relentless operator. The other still feels like the person you call when the job itself is unclear.
TL;DR
- GPT-5.6 Sol excels as a fast operator using tools for structured tasks.
- Fable 5 stands out as a senior figure for ambiguous tasks requiring judgment.
- Benchmarks show Sol leading in agentic work and knowledge tasks.
- Fable 5 performs better on tasks that are ambiguous, creative, or require judgment calls.
- GPT-5.6 is a family of models including Sol (flagship), Terra (balanced), and Luna (fast, low-cost).