Qwen3.5-397B-A17B FP8 Open Weights Now Available for Self-Hosting

Feb 18, 2026 · Updated Apr 25, 2026

Qwen3.5-397B-A17B, Alibaba's latest open-weight model, combines a sparse Mixture-of-Experts architecture with Gated Delta Networks - a hybrid linear attention design replacing standard transformer attention throughout most layers. With 512 experts and only 10+1 activated per forward pass, it runs at 17B-parameter compute cost while matching the reasoning depth of a dense frontier model. Native context is 262K tokens, extensible to 1M.

Benchmarks show it competitive with GPT-5.2, Claude 4.5 Opus, and Gemini-3 Pro across knowledge, coding, agents, and multilingual tasks - covering 201 languages. The hosted version, Qwen3.5-Plus on Alibaba Cloud, ships with 1M context and built-in tool use. The open FP8 release puts that capability in your own infrastructure.

SGLang support is merged now; vLLM support arrives in the next few days. Download weights from Hugging Face or ModelScope, check the model card for example inference code, and start experimenting.

View the full update on huggingface.co

Qwen

@Alibaba_QwenFeb 18

🚀 Qwen3.5-397B-A17B-FP8 weights are now open! It took some time to adapt the inference frameworks, but here we are: ✅ SGLang support is merged 🔄 vLLM PR submitted → https://t.co/bxbqLOENTi Check the model card for example code. vLLM support landing in the next couple of days! Hugging Face: https://t.co/porwqHuKZR ModelScope: https://t.co/E7Lr8hiyWK

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