DeepSeek V4 Flash vs Qwen3.5-397B-A17B
DeepSeek V4 Flash (2026) and Qwen3.5-397B-A17B (2026) are frontier reasoning models from DeepSeek and Alibaba. DeepSeek V4 Flash ships a 1M-token context window, while Qwen3.5-397B-A17B ships a 262K-token context window. On MMLU PRO, Qwen3.5-397B-A17B leads by 1.6 pts. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit. It focuses on practical selection signals rather than broad model-family marketing.
DeepSeek V4 Flash is safer overall; choose Qwen3.5-397B-A17B when provider fit matters.
Specs
| Released | 2026-04-24 | 2026-02-16 |
| Context window | 1M | 262K |
| Parameters | 284B | 397B |
| Architecture | mixture of experts | MoE |
| License | MIT | Apache 2.0 |
| Knowledge cutoff | - | - |
Pricing and availability
| DeepSeek V4 Flash | Qwen3.5-397B-A17B | |
|---|---|---|
| Input price | - | $0.39/1M tokens |
| Output price | - | $2.34/1M tokens |
| Providers | - |
Capabilities
| DeepSeek V4 Flash | Qwen3.5-397B-A17B | |
|---|---|---|
| Vision | ||
| Multimodal | ||
| Reasoning | ||
| Function calling | ||
| Tool use | ||
| Structured outputs | ||
| Code execution |
Benchmarks
| Benchmark | DeepSeek V4 Flash | Qwen3.5-397B-A17B |
|---|---|---|
| MMLU PRO | 86.2 | 87.8 |
| Google-Proof Q&A | 88.1 | 89.3 |
Deep dive
On shared benchmark coverage, MMLU PRO has DeepSeek V4 Flash at 86.2 and Qwen3.5-397B-A17B at 87.8, with Qwen3.5-397B-A17B ahead by 1.6 points; Google-Proof Q&A has DeepSeek V4 Flash at 88.1 and Qwen3.5-397B-A17B at 89.3, with Qwen3.5-397B-A17B ahead by 1.2 points. The largest visible gap is 1.6 points on MMLU PRO, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint differs most on multimodal input: Qwen3.5-397B-A17B, reasoning mode: DeepSeek V4 Flash, function calling: DeepSeek V4 Flash, and tool use: DeepSeek V4 Flash. Both models share structured outputs, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
Pricing coverage is uneven: DeepSeek V4 Flash has no token price sourced yet and Qwen3.5-397B-A17B has $0.39/1M input tokens. Provider availability is 0 tracked routes versus 1. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.
Choose DeepSeek V4 Flash when reasoning depth and larger context windows are central to the workload. Choose Qwen3.5-397B-A17B when provider fit and broader provider choice are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which has a larger context window, DeepSeek V4 Flash or Qwen3.5-397B-A17B?
DeepSeek V4 Flash supports 1M tokens, while Qwen3.5-397B-A17B supports 262K tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Is DeepSeek V4 Flash or Qwen3.5-397B-A17B open source?
DeepSeek V4 Flash is listed under MIT. Qwen3.5-397B-A17B is listed under Apache 2.0. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for multimodal input, DeepSeek V4 Flash or Qwen3.5-397B-A17B?
Qwen3.5-397B-A17B has the clearer documented multimodal input signal in this comparison. If multimodal input is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for reasoning mode, DeepSeek V4 Flash or Qwen3.5-397B-A17B?
DeepSeek V4 Flash has the clearer documented reasoning mode signal in this comparison. If reasoning mode is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for function calling, DeepSeek V4 Flash or Qwen3.5-397B-A17B?
DeepSeek V4 Flash has the clearer documented function calling signal in this comparison. If function calling is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run DeepSeek V4 Flash and Qwen3.5-397B-A17B?
DeepSeek V4 Flash is available on the tracked providers still being sourced. Qwen3.5-397B-A17B is available on OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Continue comparing
Last reviewed: 2026-04-24. Data sourced from public model cards and provider documentation.