StepFun Step 3.5 Flash vs SEMrush
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
SEMrush
The Swiss Army knife of SEO -- does everything from keyword research to PPC analysis, with AI sprinkled throughout
| Category | StepFun Step 3.5 Flash | SEMrush |
|---|---|---|
| Ease of Use | 6.0 | 7.0 |
| Output Quality | 8.0 | 8.0 |
| Value | 9.0 | 7.0 |
| Features | 8.0 | 10.0 |
| Overall | 7.8 | 8.0 |
Pricing Comparison
| Feature | StepFun Step 3.5 Flash | SEMrush |
|---|---|---|
| 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)
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 SEMrush if...
- ✓Easier to use (7 vs 6)
- ✓More features (10 vs 8)
Marketing teams and agencies who need one platform for SEO, PPC, and content marketing research.
Visit SEMrushOur Verdict
StepFun Step 3.5 Flash and SEMrush 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 SEMrush works best for marketing teams and agencies who need one platform for seo, ppc, and content marketing research.