Microsoft MAI-Image-2 vs StepFun Step 3.5 Flash

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

Microsoft MAI-Image-2

B
7.4/10

Microsoft's first in-house diffusion image model -- launched 2026-04-02, debuted #3 on Arena.ai leaderboard for image model families. Public preview on Azure Foundry. Powers Copilot, Bing Image Creator, and PowerPoint. Efficient variant (MAI-Image-2-Efficient) shipped 2026-04-14

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

CategoryMicrosoft MAI-Image-2StepFun Step 3.5 Flash
Ease of Use6.56.0
Output Quality8.58.0
Value7.59.0
Features7.08.0
Overall7.47.8

Pricing Comparison

FeatureMicrosoft MAI-Image-2StepFun Step 3.5 Flash
Free TierYesYes
Starting Price$5 input / $33 output$0

Which Should You Pick?

Pick Microsoft MAI-Image-2 if...

Microsoft shops already on Azure or M365 Copilot who need a first-party image model without an OpenAI dependency. Also good for any high-volume programmatic image workflow (ad creative, product photography variations) where MAI-Image-2-Efficient's 4x cost efficiency materially changes the economics.

Visit Microsoft MAI-Image-2

Pick StepFun Step 3.5 Flash if...

  • 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

Our Verdict

StepFun Step 3.5 Flash edges out Microsoft MAI-Image-2 with a 7.8 vs 7.4 overall score. Both are solid picks, but StepFun Step 3.5 Flash has the advantage in value.