Side-by-side technical and economic comparison between OpenAI's GPT-5.6 Terra and DeepSeek's DeepSeek-V4.1-Flash.
| Metric | GPT-5.6 Terra | DeepSeek-V4.1-Flash | Advantage |
|---|---|---|---|
| Provider Organization | OpenAI | 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 | $12.00 | $1.20 | DeepSeek-V4.1-Flash lower |
| Context Window | 1.05M | 1.05M | GPT-5.6 Terra (1.05M) |
| Max Generation Tokens | 16.4k | 384k | DeepSeek-V4.1-Flash |
| Tokenizer Family | OpenAI o200k_base (200k vocabulary) | DeepSeek Byte-Level BPE (100k vocabulary) | — |
Opt for GPT-5.6 Terra when your engineering requirements prioritize OpenAI's ecosystem, specific tokenizer efficiencies (Exact BPE (o200k_base)), 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.