Qwen3.5 Plus vs DeepSeek V4.1 Flash Fast
Both have similar output pricing, while DeepSeek V4.1 Flash Fast offers a larger context window. Choose Qwen3.5 Plus or DeepSeek V4.1 Flash Fast based on the trade-off between cost, context, and the benchmarks that matter for your use case.
| Spec | Qwen3.5 Plus | DeepSeek V4.1 Flash Fast |
|---|---|---|
| Provider | Alibaba | Vercel AI Gateway |
| Input / 1M tokens | $0.40 | $0.60 |
| Output / 1M tokens | $2.40 | $2.40 |
| Context window | 1M | 1M |
| Parameters | — | — |
| Open weights | No | Yes |
| Released | Feb 2026 | Sep 2026 |
| FrontierMath score | 21.0 | — |
| Epoch Capabilities Index score | 146 | — |
| GPQA Diamond score | 84.8 | — |
FAQ
Is Qwen3.5 Plus or DeepSeek V4.1 Flash Fast cheaper?
Qwen3.5 Plus and DeepSeek V4.1 Flash Fast have comparable output pricing.
Which has the larger context window, Qwen3.5 Plus or DeepSeek V4.1 Flash Fast?
DeepSeek V4.1 Flash Fast has the larger context window (1M tokens).
Pricing is indicative — confirm with the provider before production use. Highlighted values indicate the better figure for that row.