Claude Fable 5.1 vs Kimi K3
Claude Fable 5.1 vs Kimi K3: which AI model is cheaper, has the larger context window and more capabilities? Side-by-side comparison updated daily.
Quick verdict
- Kimi K3 is 3.3× cheaper than Claude Fable 5.1 for the same mix of input and output tokens.
- Kimi K3 has the larger context window (1M), useful for long documents and big codebases.
- Claude Fable 5.1 is the more recent release (Sep 1, 2026).
- Only Kimi K3 has openly published weights you can run yourself.
- Claude Fable 5.1 scores higher on independent tests (overall index 165.0 vs 157.7).
- Choose Kimi K3 if cost matters most; choose Claude Fable 5.1 if you need its specific strengths above. For the best results, test both on your own prompts.
| Claude Fable 5.1 | Kimi K3 | |
|---|---|---|
| Company | Anthropic | Moonshot AI |
| Released | Sep 1, 2026 ● | Jul 16, 2026 |
| Overall index | 165.0 ● | 157.7 |
| GPQA Diamond | — | 93.1% |
| AIME math | 100% ● | 97.2% |
| FrontierMath | 90.2% ● | 72.2% |
| SimpleQA Verified | 70.8% ● | 50.6% |
| Input (per 1M tokens) | $10 | $3 ● |
| Output (per 1M tokens) | $50 | $15 ● |
| Cost for 1M input + 1M output tokens | $60.00 | $18.00 ● |
| Providers | 4 | 22 ● |
| Context | 1M | 1M ● |
| Max output | 128K | 944K ● |
| Inputs | Text, Image, Files | Text, Image, Video |
| Outputs | Text | Text |
| Reasoning | ✓ | ✓ |
| Tool use | ✓ | ✓ |
| Structured output | ✓ | ✓ |
| Open weights | — | ✓ |