OpenAI's balanced GPT-5.6 tier — GPT-5.5-class quality for everyday work at half the price.
Anthropic's Mythos-class flagship for ambitious, long-running professional work.
No shared agent demos for these models yet.
No captured outputs for these models yet.
Both GPT 5.6 Terra and Claude Fable 5 are capable AI models. The best choice depends on your specific use case: consider pricing, context window, speed, and which capabilities (vision, reasoning, audio) you need.
GPT 5.6 Terra has a lower blended cost. GPT 5.6 Terra: $2.50 input / $15.00 output. Claude Fable 5: $10.00 input / $50.00 output.
GPT 5.6 Terra has a larger context window: GPT 5.6 Terra supports 1.1M tokens vs Claude Fable 5 at 1M tokens.
Yes, both GPT 5.6 Terra and Claude Fable 5 support vision/image input.
Key differences: GPT 5.6 Terra is significantly cheaper. Compare full specs on this page.
If cost is your priority, choose the cheaper option. If you need the highest intelligence for complex tasks, pick the higher-scoring model. For long documents or codebases, choose the larger context window. You can try both GPT 5.6 Terra and Claude Fable 5 for free on idapt.app to see which performs better for your specific needs.