Side-by-side technical and economic comparison between Anthropic's Claude Fable 5.1 and Mistral AI's Mistral Small 4.
| Metric | Claude Fable 5.1 | Mistral Small 4 | Advantage |
|---|---|---|---|
| Provider Organization | Anthropic | Mistral AI | — |
| Standard Input / 1M | $10.00 | $0.15 | Mistral Small 4 (99% lower) |
| Cached Input / 1M | $0.25 | $0.015 | Mistral Small 4 lower |
| Output / 1M | $50.00 | $0.60 | Mistral Small 4 lower |
| Context Window | 1M | 256k | Claude Fable 5.1 (1M) |
| Max Generation Tokens | 32k | 8.2k | Claude Fable 5.1 |
| Tokenizer Family | Anthropic Claude BPE (~65k vocabulary) | Mistral Tekken Tokenizer (131k vocabulary) | — |
Opt for Claude Fable 5.1 when your engineering requirements prioritize Anthropic's ecosystem, specific tokenizer efficiencies (Calibrated Claude Tokenizer (±3%)), or when your expected prompt-to-completion ratios favor its $10/M input rate.
Opt for Mistral Small 4 when looking for Mistral AI's tooling integration, specific context window depth (256k tokens), or when output generation volume favors its $0.6/M rate.