Technical Specifications of Qwen3.5‑Plus
| Item | Qwen3.5‑Plus (hosted API specs) |
|---|---|
| Model family | Qwen3.5 (Alibaba Tongyi Qianwen) |
| Architecture | Large‑scale MoE foundation with multimodal extensions |
| Input types | Text, Image (vision) |
| Output types | Text (reasoning, code, analysis) |
| Context window | Up to 1,000,000 tokens (Plus / hosted tier) |
| Max output tokens | Provider‑dependent (long‑form supported) |
| Reasoning modes | Fast / Thinking (deep reasoning) |
| Tool use | Built‑in search, code interpreter, agent workflows |
| Languages | 200+ languages |
| Deployment | Hosted API (OpenAI‑compatible format) |
What is Qwen3.5‑Plus
Qwen3.5‑Plus is the production‑grade, hosted API variant of Alibaba’s Qwen3.5 foundation model family. It is built on the same large‑scale architecture as the open‑weight Qwen3.5‑397B model, but extends it with significantly larger context capacity, adaptive reasoning modes, and integrated tool usage designed for real‑world applications.
Unlike the base open model (which typically supports up to 256K tokens), Qwen3.5‑Plus is optimized for ultra‑long‑context reasoning, autonomous agent workflows, and enterprise‑scale document and code analysis.
Main Features of Qwen3.5‑Plus
- Ultra‑long context understanding: Supports up to 1 million tokens, enabling analysis of entire codebases, large legal corpora, or multi‑day conversation logs in a single session.
- Adaptive reasoning modes: Developers can choose fast response generation or deeper “thinking” modes for complex multi‑step reasoning and planning.
- Integrated tool use: Native support for search and code interpreter tools allows the model to augment reasoning with external data and executable logic.
- Multimodal capabilities: Accepts both text and image inputs, enabling document + visual reasoning, diagram interpretation, and multimodal analysis workflows.
- Multilingual coverage: Designed for global usage, with strong performance across more than 200 languages.
- API‑ready for production: Delivered as a hosted service with OpenAI‑compatible request/response formats, reducing integration friction.
Benchmark Performance of Qwen3.5‑Plus
Public reporting from Alibaba and independent evaluations indicate that Qwen3.5‑Plus achieves competitive or superior results compared with other frontier‑class models on a range of reasoning, multilingual, and long‑context benchmarks.
Key positioning highlights:
- Strong long‑document reasoning accuracy due to extended context handling
- Competitive performance on reasoning and knowledge benchmarks relative to leading proprietary models
- Favorable cost‑to‑performance ratio for large‑scale inference workloads
Note: Exact benchmark scores vary by evaluation protocol and are periodically updated by the provider.
Qwen3.5‑Plus vs Other Frontier Models
| Model | Context Window | Strengths | Typical Trade‑offs |
|---|---|---|---|
| Qwen3.5‑Plus | 1M tokens | Long‑context reasoning, agent workflows, cost efficiency | Requires careful token management |
| Gemini 3 Pro | ~1M tokens | Strong multimodal reasoning | Higher cost in some regions |
| GPT‑5.2 Pro | ~400K tokens | Peak reasoning accuracy | Smaller context window |
Qwen3.5‑Plus is particularly attractive when context length and agent‑style workflows matter more than marginal gains in short‑context accuracy.
Known Limitations
- Token management complexity: Extremely long contexts can increase latency and cost if prompts are not carefully structured.
- Hosted‑only features: Some capabilities (e.g., 1M token context, integrated tools) are not available in open‑weight variants.
- Benchmark transparency: As with many hosted frontier models, detailed benchmark breakdowns may be limited or updated over time.
Representative Use Cases
- Enterprise document intelligence — analyze contracts, compliance archives, or research corpora end‑to‑end.
- Large‑scale code understanding — reason across monorepos, dependency graphs, and long issue histories.
- Autonomous agents — combine reasoning, tool usage, and memory for multi‑step workflows.
- Multilingual customer intelligence — process and reason over global, multilingual datasets.
- Search‑augmented analysis — integrate retrieval and reasoning for up‑to‑date insights.
How to Access Qwen3.5‑Plus via API
Qwen3.5‑Plus is accessed through hosted APIs provided by CometAPI and compatible gateways. The API generally follows OpenAI‑style request formats, enabling straightforward integration with existing SDKs and agent frameworks.
Developers should select Qwen3.5‑Plus when their applications require very long context, multimodal reasoning, and production‑ready tool orchestration.
Step 1: Sign Up for API Key
Log in to cometapi.com. If you are not our user yet, please register first. Sign into your CometAPI console. Get the access credential API key of the interface. Click “Add Token” at the API token in the personal center, get the token key: sk-xxxxx and submit.
Step 2: Send Requests to qwen3.5-plus pro API
Select the “qwen3.5-plus” endpoint to send the API request and set the request body. The request method and request body are obtained from our website API doc. Our website also provides Apifox test for your convenience. Replace <YOUR_API_KEY> with your actual CometAPI key from your account. Where to call it: Chat format.
Insert your question or request into the content field—this is what the model will respond to . Process the API response to get the generated answer.
Step 3: Retrieve and Verify Results
Process the API response to get the generated answer. After processing, the API responds with the task status and output data.