Qwen3.5-Flash overview
Qwen3.5-Flash by Alibaba Cloud
Built for real-time use cases, it delivers fast responses, strong reasoning for lightweight tasks, and excellent scalability, making it ideal for high-volume applications without sacrificing quality.
Qwen3.5-Flash specs
- Model ID
alibaba/qwen3.5-flash- Developer
- Alibaba Cloud
- Context window
- 1,000,000 tokens
- Max output
- 65,536 tokens
- Input
- Text, Image
- Output
- Text
- API
- OpenAI-compatible, base URL
https://api.aimlapi.com/v1
What exactly is Qwen3.5-Flash?
Qwen3.5-Flash is the hosted, production-grade API version of Alibaba's Qwen3.5-35B-A3B open-weight model. While the underlying open-weight model carries 35 billion total parameters, it activates only around 3 billion per forward pass, a characteristic of its sparse Mixture-of-Experts (MoE) design that keeps inference fast and affordable without meaningful quality sacrifice.
The "Flash" name signals where this model sits in the lineup: it is optimized for throughput, low latency, and cost at scale. It ships with a 1M-token context window by default, native multimodal support for text, images, and video, built-in tool-calling, and configurable chain-of-thought reasoning. These are not experimental features, they are production defaults, ready to use from the first API call.
Architecture: what makes it fast and cheap
Qwen3.5-Flash does not follow a standard dense transformer architecture. It uses a hybrid design that combines two distinct attention mechanisms in a fixed 3:1 ratio, three linear attention layers for every one full self-attention layer.
Gated DeltaNet (linear attention)
Compresses context into fixed-size recurrent states rather than growing KV-caches. This dramatically reduces memory overhead, especially for very long sequences. Processing a 500K-token document costs roughly 3–4x more than a 50K document, not 100x as with standard attention.
Sparse MoE (mixture of experts)
Each token is routed to a small subset of specialized "expert" sub-networks within the 35B parameter space. With only 8.6% of total parameters active per forward pass, the model achieves GPT-5-mini-class reasoning at a fraction of the raw compute cost.
Native multimodal fusion
Text, images, and short video segments are processed in a single forward pass. There are no separate vision adapters or preprocessing pipelines, the model was trained from scratch on multimodal tokens using early fusion, allowing natural cross-modal reasoning.
Configurable reasoning depth
Callers can dial reasoning intensity up or down per request. At low settings the model behaves as a fast instruction-follower; at higher settings it performs multi-step chain-of-thought decomposition suited for math, coding, and agentic planning tasks.
Use cases
Code assistance and agentic workflows: Alibaba Cloud says Qwen3.5-Flash “shines in coding assistance” and “agentic workflows,” including fixing code autonomously and operating desktop applications.
Visual understanding: Alibaba Cloud documents Qwen3.5-Flash as a native vision-language model for visual understanding, and its model lifecycle notes mention analyzing charts and long videos.
Text generation and reasoning: Alibaba Cloud lists Qwen3.5-Flash under text generation with thinking mode and supports it for reasoning, making it suitable for general text-generation tasks that require structured output and tool use.
Multimodal document workflows: Public listings describe the model as accepting text, images, and video, and position it for multimodal document workflows that combine mixed text, image, and video inputs.
Capabilities
- Function calling
- Streaming
- Structured outputs
- Reasoning
- Web search
Qwen3.5-Flash API pricing
| Usage | Price | Unit |
|---|---|---|
| Input | $0.1 | 1M tokens |
| Output | $0.4 | 1M tokens |
Prices from the AI/ML API price list, checked on Nov 4, 2026.
Qwen3.5-Flash vs other models: token prices
AI/ML API input and output rates for 5 models, per million tokens.
| Model | Input | Output |
|---|---|---|
 Qwen3.5-Flash | $0.1 | $0.4 |
| Qwen3.8 Omni Flash | $0.15 | $0.47 |
| Qwen3.8-Flash | $0.16 | $0.47 |
| Qwen 3.8 27B | $0.4761 | $3.39 |
| Qwen3.8 Max Prime | $4.23 | $12.7 |
How to use the Qwen3.5-Flash API
View docs
Build with your agent
Give your agent the model details, code and documentation.
1Get your API key
Create API keyexport AIMLAPI_KEY="8f2b4c7d9a1e6b3f…"2Make your first request
curl 'https://api.aimlapi.com/v1/chat/completions' \
-H "Authorization: Bearer $AIMLAPI_KEY" \
-H 'Content-Type: application/json' \
-d '{
"model": "alibaba/qwen3.5-flash",
"messages": [
{
"role": "user",
"content": "Write a haiku about the ocean."
}
]
}'import os
import requests
headers = {
"Authorization": f"Bearer {os.environ['AIMLAPI_KEY']}",
"Content-Type": "application/json",
}
payload = {
"model": "alibaba/qwen3.5-flash",
"messages": [
{
"role": "user",
"content": "Write a haiku about the ocean."
}
]
}
response = requests.post("https://api.aimlapi.com/v1/chat/completions", headers=headers, json=payload, timeout=120)
response.raise_for_status()
print(response.json())const response = await fetch("https://api.aimlapi.com/v1/chat/completions", {
method: "POST",
headers: {
Authorization: `Bearer ${process.env.AIMLAPI_KEY}`,
"Content-Type": "application/json",
},
body: JSON.stringify({
"model": "alibaba/qwen3.5-flash",
"messages": [
{
"role": "user",
"content": "Write a haiku about the ocean."
}
]
}),
});
if (!response.ok) throw new Error(`HTTP ${response.status}`);
console.log(await response.json());Models similar to Qwen3.5-Flash
Related articles
Qwen3.5-Flash FAQ
What is the context window of Qwen3.5-Flash?
Qwen3.5-Flash has a 1,000,000 tokens context window and can return up to 65,536 tokens.
What inputs and outputs does Qwen3.5-Flash support?
Qwen3.5-Flash takes image, text as input and returns text.
What is the model ID for Qwen3.5-Flash?
Use alibaba/qwen3.5-flash as the model id. Requests go to https://api.aimlapi.com/v1/chat/completions.
When was Qwen3.5-Flash released?
Qwen3.5-Flash became available on April 21, 2026.
How much does Qwen3.5-Flash cost?
Qwen3.5-Flash costs $0.1 input and $0.4 output per 1M tokens on AI/ML API, billed as you go with no subscription.
Does Qwen3.5-Flash support streaming?
Yes, Qwen3.5-Flash can stream responses as they are generated.
Can Qwen3.5-Flash read images?
Yes, Qwen3.5-Flash accepts image input alongside text.
Who created Qwen3.5-Flash?
Qwen3.5-Flash was built by Alibaba Cloud.
Does Qwen3.5-Flash support function or tool calling?
Yes, it supports tool calling, including parallel tool calls.
Can Qwen3.5-Flash process video input?
No, its supported modalities are image and text input to text output; video is not listed.