StepFun Step 3.5 Flash vs Hunyuan 3 (Tencent Hy3)
Which one should you pick? Here's the full breakdown.
StepFun Step 3.5 Flash
StepFun's (China) agent-focused open-weight model -- Step 3.5 Flash launched 2026-02-01. 196B sparse MoE, ~11B active. Benchmarks slightly ahead of DeepSeek V3.2 at over 3x smaller total size. Step 3 (321B / 38B active, Apache 2.0) and Step3-VL-10B multimodal also in the family
Hunyuan 3 (Tencent Hy3)
Tencent's Hy3 Preview launched 2026-04-23 -- 295B total / 21B active MoE, 256K context, open-sourced on HuggingFace under tencent/Hy3-preview. Cheapest frontier-class API at ~1.2 RMB per million input tokens. Integrated into Yuanbao, WeChat, QQ
| Category | StepFun Step 3.5 Flash | Hunyuan 3 (Tencent Hy3) |
|---|---|---|
| Ease of Use | 6.0 | 7.0 |
| Output Quality | 8.0 | 8.0 |
| Value | 9.0 | 9.5 |
| Features | 8.0 | 8.0 |
| Overall | 7.8 | 8.1 |
Pricing Comparison
| Feature | StepFun Step 3.5 Flash | Hunyuan 3 (Tencent Hy3) |
|---|---|---|
| Free Tier | Yes | Yes |
| Starting Price | $0 | $0 |
Which Should You Pick?
Pick StepFun Step 3.5 Flash if...
Teams building agent systems on Chinese open-weight foundations who want something other than DeepSeek or Qwen, especially if agentic tool-use is the primary workload. Also good for Chinese-market products where StepFun's domestic tuning advantages matter. And for anyone looking to add diversity to their open-weight evaluation matrix beyond the top-3 Chinese labs.
Visit StepFun Step 3.5 FlashPick Hunyuan 3 (Tencent Hy3) if...
- ✓Easier to use (7 vs 6)
Chinese-market builders, multilingual products that need strong CN performance, and cost-sensitive developers who want frontier-class quality at sub-DeepSeek pricing. Also anyone watching the open-weights field who wants Tencent's distribution-backed entry on the bench.
Visit Hunyuan 3 (Tencent Hy3)Our Verdict
StepFun Step 3.5 Flash and Hunyuan 3 (Tencent Hy3) are extremely close overall. Your choice comes down to specific needs -- StepFun Step 3.5 Flash is better for teams building agent systems on chinese open-weight foundations who want something other than deepseek or qwen, especially if agentic tool-use is the primary workload, while Hunyuan 3 (Tencent Hy3) works best for chinese-market builders, multilingual products that need strong cn performance, and cost-sensitive developers who want frontier-class quality at sub-deepseek pricing.