Claude 3.7 Sonnet vs Qwen3.5-397B-A17B

Claude 3.7 Sonnet

Anthropic

Claude Sonnet 3.7, released by Anthropic in February 2025, is a large language model from the Claude 3 family featuring hybrid reasoning with configurable extended thinking. It supports a 200K token context window, 64K maximum output tokens (128K in beta), and native image understanding. Sonnet 3.7 targets complex coding, mathematics, and scientific reasoning tasks where extended chain-of-thought processing provides meaningful improvements in output quality.

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.