Qwen 3.5 vs DeepSeek V4
Comprehensive comparison between Alibaba (Qwen)'s Qwen 3.5 and DeepSeek's DeepSeek V4. Compare pricing, performance, features, and user reviews.
Qwen 3.5
Alibaba (Qwen)Alibaba's flagship open-source MoE model with 397B total parameters (17B active per pass). Apache 2.0 licensed for commercial use. Supports 201 languages with native vision capabilities. Best open-weight model for local deployment.
DeepSeek V4
DeepSeekDeepSeek V4 (released 2026-04-24) ships two MIT-licensed MoE variants: V4-Pro (1.6T/49B active) and V4-Flash (284B/13B active), both with 1M-token context and hybrid Compressed Sparse Attention + Heavily Compressed Attention. Three reasoning modes (Non-think / Think High / Think Max). V4-Pro uses only 27% of V3.2's FLOPs and 10% of its KV cache at 1M context. Priced well below GPT-5.5 / Opus 4.7 while matching them on most benchmarks.
Specs Comparison
| Specification | Qwen 3.5 | DeepSeek V4 |
|---|---|---|
| Context Window | 262K | 1000K |
| Max Output | 32K | 66K |
| Input (per 1M tokens) | $0.39 | $1.74 |
| Output (per 1M tokens) | $1.56 | $3.48 |
| Reasoning | ||
| Open Source |
Scenario Score Comparison
Qwen 3.5
Pros
- + Open source (Apache 2.0)
- + Self-hostable with vLLM
- + 201 language support
- + MoE efficiency (17B active)
- + Cheapest API among frontier-class
- + Strong vision/multimodal performance
Cons
- − Weaker on hard coding tasks vs Opus/GPT
- − Requires significant VRAM for local hosting
- − Quantization affects complex reasoning
- − Smaller context than GPT-5.4/Opus 4.6
DeepSeek V4
Pros
- + 1M token context window with aggressive KV-cache compression
- + MIT license — fully open-source, self-hostable
- + V4-Pro $1.74/$3.48 per MTok — far cheaper than GPT-5.5 and Opus 4.7
- + New SOTA for open models on SimpleQA-Verified (57.9)
- + OpenAI + Anthropic API-compatible endpoints
- + Three reasoning modes tunable per request
Cons
- − Still trails GPT-5.4 / Gemini 3.1 Pro by 3-6 months on frontier benchmarks
- − Servers in China (overseas latency, geopolitical concerns)
- − Text-only — V3's multimodal (image/video) capability not confirmed for V4
- − V4-Pro self-hosting needs substantial hardware (49B active × FP4/FP8)
Recommendation
Choose Qwen 3.5 if you:
- • Need open source (apache 2.0)
- • Need self-hostable with vllm
- • Need 201 language support
Choose DeepSeek V4 if you:
- • Need 1m token context window with aggressive kv-cache compression
- • Need mit license — fully open-source, self-hostable
- • Need v4-pro $1.74/$3.48 per mtok — far cheaper than gpt-5.5 and opus 4.7
Based on scores across 2 scenarios, Qwen 3.5 performs better overall.
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