Side-by-side technical and economic comparison between Anthropic's Claude Sonnet 5 and DeepSeek's DeepSeek-V4.1-Flash.
| Metric | Claude Sonnet 5 | DeepSeek-V4.1-Flash | Advantage |
|---|---|---|---|
| Provider Organization | Anthropic | DeepSeek | — |
| Standard Input / 1M | $2.00 | $0.30 | DeepSeek-V4.1-Flash (85% lower) |
| Cached Input / 1M | $0.20 | $0.006 | DeepSeek-V4.1-Flash lower |
| Output / 1M | $10.00 | $1.20 | DeepSeek-V4.1-Flash lower |
| Context Window | 1M | 1.05M | DeepSeek-V4.1-Flash (1.05M) |
| Max Generation Tokens | 16.4k | 384k | DeepSeek-V4.1-Flash |
| Tokenizer Family | Anthropic Claude BPE (~65k vocabulary) | DeepSeek Byte-Level BPE (100k vocabulary) | — |
Opt for Claude Sonnet 5 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 $2/M input rate.
Opt for DeepSeek-V4.1-Flash when looking for DeepSeek's tooling integration, specific context window depth (1.05M tokens), or when output generation volume favors its $1.2/M rate.