OpenAI's fastest, most affordable GPT-5.6 tier for high-volume, latency-sensitive work.
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 Luna 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 Luna has a lower blended cost. GPT 5.6 Luna: $1.00 input / $6.00 output. Claude Fable 5: $10.00 input / $50.00 output.
GPT 5.6 Luna has a larger context window: GPT 5.6 Luna supports 1.1M tokens vs Claude Fable 5 at 1M tokens.
Yes, both GPT 5.6 Luna and Claude Fable 5 support vision/image input.
Key differences: GPT 5.6 Luna 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 Luna and Claude Fable 5 for free on idapt.app to see which performs better for your specific needs.