StepFun Step 3.5 Flash vs Udio
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
Udio
AI music generation that leans harder into audio fidelity and sonic detail than the competition
| Category | StepFun Step 3.5 Flash | Udio |
|---|---|---|
| Ease of Use | 6.0 | 7.0 |
| Output Quality | 8.0 | 8.0 |
| Value | 9.0 | 7.0 |
| Features | 8.0 | 7.0 |
| Overall | 7.8 | 7.3 |
Pricing Comparison
| Feature | StepFun Step 3.5 Flash | Udio |
|---|---|---|
| Free Tier | Yes | Yes |
| Starting Price | $0 | $0 |
Which Should You Pick?
Pick StepFun Step 3.5 Flash if...
- ✓Better value for money (9/10)
- ✓More features (8 vs 7)
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 Udio if...
- ✓Easier to use (7 vs 6)
Music enthusiasts and producers who want higher audio fidelity and more nuanced genre handling from AI.
Visit UdioOur Verdict
StepFun Step 3.5 Flash edges out Udio with a 7.8 vs 7.3 overall score. Both are solid picks, but StepFun Step 3.5 Flash has the advantage in value.