Qwen3.5-397B-A17B vs Seed 2.0 Pro

Alibaba / Qwen

Qwen3.5-397B-A17B is a 397-billion-parameter mixture-of-experts model from Alibaba's Qwen team, released in February 2026 as the open-weight flagship of the Qwen3.5 series, featuring 17 billion active parameters per forward pass through a hybrid linear-attention and sparse-MoE architecture based on Gated Delta Networks. The model was co-trained on text, images, and video using early fusion, making it natively multimodal across a 262K token context window, while achieving significantly higher inference throughput than comparable dense models due to its sparse computation design. At release it was one of the most capable open-weight models publicly available, offered under Apache 2.0 and accessible through Alibaba's DashScope API as the Qwen3.5-Plus endpoint.

ByteDance

Seed 2.0 Pro is ByteDance's flagship general-purpose model, released in February 2026 under the Doubao brand through the Volcengine API platform, developed by the company's Seed research team as a foundation for agentic applications requiring long-horizon reasoning and multimodal input comprehension. The model accepts text, images, and extended video — including hour-length recordings — targeting enterprise use cases in long-form document analysis, agentic coding (integrated with ByteDance's TRAE IDE), and multi-turn reasoning tasks. It anchors a three-tier product family alongside Seed 2.0 Lite and Mini, positioned as ByteDance's response to frontier model competition in the Chinese and global enterprise AI markets.