Anthropic's Mythos-class flagship for ambitious, long-running professional work.
o3-mini with reasoning effort set to high for maximum STEM accuracy.
No shared demos for these models yet.
No captured outputs for these models yet.
Based on the Capability Index, Claude Fable 5 scores higher (91.6 vs 73.9). However, "better" depends on your use case — pricing, speed, context window, and specific capability needs all matter.
o3-mini (High) has a lower blended cost. Claude Fable 5: $10.00 input / $50.00 output. o3-mini (High): $1.10 input / $4.40 output.
Claude Fable 5 has a larger context window: Claude Fable 5 supports 1M tokens vs o3-mini (High) at 200K tokens.
Claude Fable 5 supports vision/image input, but o3-mini (High) does not.
Key differences: Claude Fable 5 has a notably higher capability index (17.7 point gap); o3-mini (High) is significantly cheaper; only Claude Fable 5 supports vision input. 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 Claude Fable 5 and o3-mini (High) for free on idapt.app to see which performs better for your specific needs.