FlagshipOpen SourceAlibaba

Qwen 3.5 397B

Qwen 3.5 397B is Alibaba's flagship open-source language model with 397 billion parameters, offering tool calling and a 128K token context window.

Context 128K
Tier Flagship
Tools Supported
License Open Source
Input from
$0.390 / 1M tokens
across 2 providers

API Pricing

Cheapest on OpenRouter 21% below avg
ProviderInput / 1MOutput / 1MUpdated
$0.390$2.344/14/2026
$0.600$3.604/14/2026

Prices updated daily. Last check: 4/14/2026

Model Details

General

Creator
Alibaba
Family
Qwen
Tier
Flagship
Context Window
128K
Modalities
Text

Capabilities

Tool Calling
Yes
Open Source
Yes
Subtypes
Chat Completion, Code Generation
Aliases
qwen3-5-397b-a17b

Strengths & Limitations

  • 397 billion parameters provide substantial model capacity for complex reasoning tasks
  • Open-source license allows local deployment and custom fine-tuning
  • Tool calling support enables integration with external APIs and functions
  • 128K token context window handles lengthy documents and conversations
  • Supports both chat completion and code generation modalities
  • No vendor lock-in or API dependency requirements
  • Model weights available for download and self-hosting
  • Text-only input lacks multimodal capabilities like image or audio processing
  • Requires significant computational resources due to 397B parameter size
  • Smaller context window compared to some competing flagship models
  • Self-hosting demands substantial GPU memory and infrastructure investment
  • May have slower inference speeds than smaller models in the family

Key Features

397 billion parameter architecture
128,000 token context window
Tool calling with function execution
Chat completion API compatibility
Code generation and programming assistance
Open-source model weights
Streaming response support
Custom fine-tuning capabilities

About Qwen 3.5 397B

Qwen 3.5 397B is Alibaba's flagship model in the Qwen family, featuring 397 billion parameters in an open-source architecture. As the largest model in the Qwen 3.5 series, it represents Alibaba's most capable offering for complex reasoning and generation tasks. The model supports text-only input with a 128,000 token context window and includes tool calling capabilities. It handles both chat completion and code generation workloads, with the parameter scale designed to deliver strong performance across reasoning, mathematics, and programming tasks. The open-source nature allows for local deployment and fine-tuning. Qwen 3.5 397B competes with other large-scale open models in the 300B+ parameter range, offering an alternative to proprietary flagship models for organizations requiring local deployment or model customization. Its substantial parameter count positions it for complex multi-step reasoning and agentic workflows that benefit from the model's scale.

Common Use Cases

Qwen 3.5 397B is designed for organizations requiring a flagship-tier model with local deployment capabilities. Its 397B parameter scale makes it suitable for complex reasoning tasks, multi-step problem solving, and sophisticated code generation where model capability is prioritized over inference speed. The open-source nature makes it valuable for research institutions, enterprises with strict data privacy requirements, and developers building custom AI applications that need fine-tuning capabilities. The tool calling feature enables agentic workflows and integration with existing software systems, while the substantial parameter count supports demanding applications like advanced mathematical reasoning, complex document analysis, and multi-turn coding assistance.

Frequently Asked Questions

How much does Qwen 3.5 397B cost per million tokens?

Qwen 3.5 397B pricing varies by provider and deployment method, with some offering hosted API access while others provide infrastructure for self-hosting the open-source model. Check the pricing table above for current rates across all available providers.

What is Qwen 3.5 397B best used for?

Qwen 3.5 397B excels at complex reasoning tasks, advanced code generation, and multi-step problem solving where its 397B parameter scale provides advantages. It's particularly valuable for organizations needing flagship-tier capabilities with local deployment options, research applications requiring model customization, and agentic workflows leveraging its tool calling features.

What are the hardware requirements for running Qwen 3.5 397B locally?

Running Qwen 3.5 397B requires substantial GPU memory due to its 397 billion parameters. The exact requirements depend on precision (FP16, INT8, etc.) and serving configuration, but expect to need multiple high-memory GPUs or specialized inference hardware for practical deployment speeds.