StepFun Step 3.5 Flash vs Captions

Which one should you pick? Here's the full breakdown.

Our Pick

StepFun Step 3.5 Flash

B
7.8/10

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

Captions

C
6.5/10

AI video editor with auto captions, eye contact correction, and dubbing for talking-head content

CategoryStepFun Step 3.5 FlashCaptions
Ease of Use6.08.0
Output Quality8.06.0
Value9.05.0
Features8.07.0
Overall7.86.5

Pricing Comparison

FeatureStepFun Step 3.5 FlashCaptions
Free TierYesYes
Starting Price$0$0

Which Should You Pick?

Pick StepFun Step 3.5 Flash if...

  • Higher output quality (8 vs 6)
  • Better value for money (9/10)
  • More features (8 vs 7)

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 Flash

Pick Captions if...

  • Easier to use (8 vs 6)

Short-form content creators who mostly do talking-head videos and need polished captions fast. If you stick to the caption features, it does that job well.

Visit Captions

Our Verdict

StepFun Step 3.5 Flash is the clear winner here with 7.8/10 vs 6.5/10. Captions isn't bad, but StepFun Step 3.5 Flash outperforms it across the board. Pick Captions only if short-form content creators who mostly do talking-head videos and need polished captions fast.