Skywork-R1V3-38B vs Step-3.5-Flash

Kunlun Tech

Skywork-R1V3-38B, released by Kunlun Tech's Skywork AI team on July 9, 2025, is a 38 billion parameter multimodal reasoning model built on InternVL-38B with reinforcement learning post-training that enhances both visual and textual reasoning. It uses the GRPO algorithm and cold-start fine-tuning to improve reasoning across image and text modalities. Skywork-R1V3-38B targets open-source multimodal reasoning deployments requiring strong performance across vision-language benchmarks.

StepFun

Step-3.5-Flash, released by StepFun on February 2, 2026, is a Mixture-of-Experts large language model with 197 billion total parameters and approximately 11 billion active parameters per inference. It features a 256K token context window using a 3:1 sliding-window-to-full-attention ratio, processing 100–350 tokens per second. Step-3.5-Flash targets agentic tasks, coding workflows, and open-source deployments requiring frontier reasoning capabilities with efficient inference, under an Apache 2.0 license.