StepFun Step 3.5 Flash vs MiMo (Xiaomi)
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
MiMo (Xiaomi)
Xiaomi's MiMo-V2.5 family launched 2026-04-22 -- Pro (1T total / 42B active MoE, 1M context, native vision+audio reasoning), Multimodal base, TTS (3 sub-models: base, VoiceDesign, VoiceClone), and ASR (open-source, English + Chinese + major dialects). Full voice pipeline for the agent era. Extra-charge 1M-context tier removed at launch
| Category | StepFun Step 3.5 Flash | MiMo (Xiaomi) |
|---|---|---|
| Ease of Use | 6.0 | 7.0 |
| Output Quality | 8.0 | 8.0 |
| Value | 9.0 | 9.0 |
| Features | 8.0 | 9.0 |
| Overall | 7.8 | 8.3 |
Pricing Comparison
| Feature | StepFun Step 3.5 Flash | MiMo (Xiaomi) |
|---|---|---|
| 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 MiMo (Xiaomi) if...
- ✓Easier to use (7 vs 6)
- ✓More features (9 vs 8)
Teams building voice-first agentic products that need a coordinated reasoning + TTS + ASR stack from a single vendor. Also Chinese-market builders and developers who need strong multimodal (vision + audio) inputs in one API call without stitching three providers together. The no-surcharge 1M-context stance makes MiMo-V2.5-Pro especially attractive for long-document agentic workloads.
Visit MiMo (Xiaomi)Our Verdict
MiMo (Xiaomi) edges out StepFun Step 3.5 Flash with a 8.3 vs 7.8 overall score. Both are solid picks, but MiMo (Xiaomi) has the advantage in features.