GPT-Rosalind (OpenAI) vs StepFun Step 3.5 Flash
Which one should you pick? Here's the full breakdown.
GPT-Rosalind (OpenAI)
OpenAI's first domain-specific model -- life sciences, drug discovery, translational medicine. Launched 2026-04-16 as a Trusted Access research preview. Launch partners: Amgen, Moderna, Allen Institute, Thermo Fisher. Paired with a Life Sciences Codex plugin (50+ scientific tool integrations)
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 | GPT-Rosalind (OpenAI) | StepFun Step 3.5 Flash |
|---|---|---|
| Ease of Use | 3.0 | 6.0 |
| Output Quality | 9.0 | 8.0 |
| Value | 7.0 | 9.0 |
| Features | 8.0 | 8.0 |
| Overall | 6.8 | 7.8 |
Pricing Comparison
| Feature | GPT-Rosalind (OpenAI) | StepFun Step 3.5 Flash |
|---|---|---|
| Free Tier | No | Yes |
| Starting Price | Invite only | $0 |
Which Should You Pick?
Pick GPT-Rosalind (OpenAI) if...
- ✓Higher output quality (9 vs 8)
Researchers and enterprises in biology, drug discovery, protein science, translational medicine, or adjacent life-sciences domains who can get Trusted Access. Also relevant to anyone building life-sciences AI products who needs to understand where OpenAI's vertical strategy is heading.
Visit GPT-Rosalind (OpenAI)Pick StepFun Step 3.5 Flash if...
- ✓Easier to use (6 vs 3)
- ✓Better value for money (9/10)
- ✓Has a free tier
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
StepFun Step 3.5 Flash is the clear winner here with 7.8/10 vs 6.8/10. GPT-Rosalind (OpenAI) isn't bad, but StepFun Step 3.5 Flash outperforms it across the board. Pick GPT-Rosalind (OpenAI) only if researchers and enterprises in biology, drug discovery, protein science, translational medicine, or adjacent life-sciences domains who can get trusted access.