StepFun Step 3.5 Flash vs HeyGen
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
HeyGen
AI avatar videos for marketing and sales -- like Synthesia but with better lip-sync and more personality
| Category | StepFun Step 3.5 Flash | HeyGen |
|---|---|---|
| Ease of Use | 6.0 | 8.0 |
| Output Quality | 8.0 | 7.0 |
| Value | 9.0 | 6.0 |
| Features | 8.0 | 8.0 |
| Overall | 7.8 | 7.3 |
Pricing Comparison
| Feature | StepFun Step 3.5 Flash | HeyGen |
|---|---|---|
| Free Tier | Yes | Yes |
| Starting Price | $0 | $0 |
Which Should You Pick?
Pick StepFun Step 3.5 Flash if...
- ✓Higher output quality (8 vs 7)
- ✓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 HeyGen if...
- ✓Easier to use (8 vs 6)
Marketing teams and sales orgs who need personalized video content at scale, especially for multilingual campaigns.
Visit HeyGenOur Verdict
StepFun Step 3.5 Flash edges out HeyGen with a 7.8 vs 7.3 overall score. Both are solid picks, but StepFun Step 3.5 Flash has the advantage in output quality.