IBM Granite 4.0 vs StepFun Step 3.5 Flash
Which one should you pick? Here's the full breakdown.
IBM Granite 4.0
IBM's enterprise-focused open-weight family -- Granite 4.0 hybrid Mamba-2 + transformer architecture (70-80% memory reduction vs pure transformer), 3B to 32B sizes, Apache 2.0. First open model family to secure ISO 42001 certification. Nano 350M runs on CPU with 8-16GB RAM. 3B Vision variant landed 2026-04-01
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
| Category | IBM Granite 4.0 | StepFun Step 3.5 Flash |
|---|---|---|
| Ease of Use | 7.0 | 6.0 |
| Output Quality | 8.0 | 8.0 |
| Value | 9.5 | 9.0 |
| Features | 8.5 | 8.0 |
| Overall | 8.2 | 7.8 |
Pricing Comparison
| Feature | IBM Granite 4.0 | StepFun Step 3.5 Flash |
|---|---|---|
| Free Tier | Yes | Yes |
| Starting Price | $0 | $0 |
Which Should You Pick?
Pick IBM Granite 4.0 if...
- ✓Easier to use (7 vs 6)
Regulated-industry enterprises (healthcare, finance, government) who need Apache 2.0 open-weight models with ISO 42001 certification. Also ideal for edge deployments where Granite Nano (350M / 1.5B) is one of the few open models that runs realistically on CPU. And for any Mamba-hybrid research or low-memory production use where the 70-80% memory reduction actually changes the economics.
Visit IBM Granite 4.0Pick 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 FlashOur Verdict
IBM Granite 4.0 edges out StepFun Step 3.5 Flash with a 8.2 vs 7.8 overall score. Both are solid picks, but IBM Granite 4.0 has the advantage in value.