FAQ

Frequently asked questions about Qwen3-VL models and usage

General Questions

What is Qwen3-VL?

Qwen3-VL is the most powerful vision-language model in the Qwen series. It delivers comprehensive upgrades including:

• Superior text understanding & generation
• Deeper visual perception & reasoning
• Extended context length (256K native, expandable to 1M)
• Enhanced spatial and video dynamics comprehension
• Stronger agent interaction capabilities

Available in Dense and MoE architectures ranging from 2B to 235B parameters, with both Instruct and Thinking editions.

What’s the difference between Qwen3-VL and Qwen2.5-VL?

Qwen3-VL introduces several architectural improvements:

1. Interleaved-MRoPE: Enhanced positional embeddings for better video reasoning
2. DeepStack: Multi-level ViT feature fusion for finer details
3. Text-Timestamp Alignment: Precise temporal modeling for videos
4. Improved Capabilities: Better visual coding, spatial reasoning, OCR (32 languages vs 10)
5. Larger Model Sizes: Up to 235B parameters with MoE architecture

See the technical paper for detailed comparisons.

Which model should I use?

For edge/mobile deployment: Qwen3-VL-2B

• Smallest footprint
• Suitable for consumer GPUs

For balanced performance: Qwen3-VL-4B or Qwen3-VL-8B

• Good performance-to-resource ratio
• RTX 3090/4090, A100 40GB

For high performance: Qwen3-VL-32B or Qwen3-VL-30B-A3B

• Strong capabilities
• 30B-A3B uses MoE with only 3B active

For maximum capability: Qwen3-VL-235B-A22B

• State-of-the-art performance
• Requires 8x H100/H200

Should I use Instruct or Thinking edition?

Instruct Edition:

• General-purpose applications
• Better instruction following
• More aligned with human preferences
• Faster inference

Thinking Edition:

• Complex reasoning tasks
• STEM and mathematical problems
• Causal analysis and logical reasoning
• Provides detailed thought processes

Model Capabilities

What visual tasks does Qwen3-VL support?

• Image Understanding: Object recognition, scene understanding, visual reasoning
• OCR: 32 languages, robust to blur/tilt/low-light
• Document Parsing: Layout analysis, structure extraction
• Object Grounding: 2D bounding boxes and points, 3D spatial reasoning
• Video Understanding: Long-form video (hours), temporal reasoning, second-level indexing
• Visual Coding: Generate HTML/CSS/JS/Draw.io from screenshots
• Agent Tasks: GUI interaction, tool use on PC/mobile
• Spatial Reasoning: Viewpoint, occlusion, 3D relationships

What is the maximum context length?

Default: 256K tokens

Extended: Up to 1M tokens using YaRN scaling

To enable 1M context, modify config.json:

{
    "max_position_embeddings": 1000000,
    "rope_scaling": {
        "rope_type": "yarn",
        "mrope_section": [24, 20, 20],
        "mrope_interleaved": true,
        "factor": 3.0,
        "original_max_position_embeddings": 262144
    }
}

See Troubleshooting: Context Length for details.

How many images/videos can I process at once?

Qwen3-VL supports multiple images and videos in a single conversation, limited only by context length.

Example with multiple inputs:

messages = [
    {
        "role": "user",
        "content": [
            {"type": "image", "image": "file:///path/to/img1.jpg"},
            {"type": "image", "image": "file:///path/to/img2.jpg"},
            {"type": "video", "video": "file:///path/to/video.mp4"},
            {"type": "text", "text": "Compare these images and describe the video."},
        ],
    }
]

Control visual token budget to manage context usage - see Advanced Usage.

What languages does the OCR support?

Qwen3-VL supports OCR in 32 languages (expanded from 10 in Qwen2.5-VL), including:

• Major world languages (English, Chinese, Spanish, French, German, etc.)
• Asian languages (Japanese, Korean, Thai, Vietnamese, etc.)
• Arabic, Hebrew, Cyrillic scripts
• Rare and ancient characters
• Technical jargon and specialized terminology

Robust performance in challenging conditions: blur, tilt, low-light, handwriting.

Installation & Setup

What are the minimum requirements?

Software:

• Python 3.8+
• PyTorch 2.0+
• Transformers >= 4.57.0
• CUDA 11.6+ (for GPU)

Hardware (varies by model size):

• Qwen3-VL-2B: 8GB+ VRAM (consumer GPU)
• Qwen3-VL-8B: 24GB+ VRAM (RTX 3090/4090)
• Qwen3-VL-32B: 80GB+ VRAM (A100 80GB or multi-GPU)
• Qwen3-VL-235B-A22B: 8x H100/H200 recommended

See Troubleshooting: GPU Requirements.

How do I install Qwen3-VL?

Basic installation:

pip install "transformers>=4.57.0" accelerate qwen-vl-utils

For video support:

# Recommended: torchcodec (fastest)
# See https://github.com/pytorch/torchcodec

# Or: decord (Linux PyPI, others build from source)
pip install qwen-vl-utils[decord]

For deployment:

pip install vllm>=0.11.0  # or sglang

See Installation Guide for details.

Where can I download the models?

HuggingFace (global):

• Qwen3-VL Collection

ModelScope (optimized for mainland China):

• Qwen3-VL Collection

All models available in:

• Base precision (BF16/FP16)
• FP8 quantized (for H100/H200)

See Model Cards for complete list.

Usage

How do I run inference?

Basic inference:

from transformers import AutoModelForImageTextToText, AutoProcessor

model = AutoModelForImageTextToText.from_pretrained(
    "Qwen/Qwen3-VL-8B-Instruct",
    dtype="auto",
    device_map="auto"
)
processor = AutoProcessor.from_pretrained("Qwen/Qwen3-VL-8B-Instruct")

messages = [
    {
        "role": "user",
        "content": [
            {"type": "image", "image": "https://example.com/image.jpg"},
            {"type": "text", "text": "Describe this image."},
        ],
    }
]

inputs = processor.apply_chat_template(
    messages, tokenize=True, add_generation_prompt=True, return_tensors="pt"
)
inputs = inputs.to(model.device)

generated_ids = model.generate(**inputs, max_new_tokens=128)
output = processor.batch_decode(
    [out[len(inp):] for inp, out in zip(inputs.input_ids, generated_ids)],
    skip_special_tokens=True
)
print(output)

See Quickstart for more examples.

How do I control image/video resolution?

Method 1: Global settings via processor

# For images
processor.image_processor.size = {
    "longest_edge": 1280*32*32,  # max_pixels
    "shortest_edge": 256*32*32   # min_pixels
}

# For videos
processor.video_processor.size = {
    "longest_edge": 16384*32*32*2,
    "shortest_edge": 256*32*32*2
}

Method 2: Per-input with qwen-vl-utils

messages = [
    {
        "role": "user",
        "content": [
            {
                "type": "image",
                "image": "path/to/image.jpg",
                "min_pixels": 50176,
                "max_pixels": 50176,
            },
            {"type": "text", "text": "Describe this image."},
        ],
    }
]

See Advanced: Vision Encoder Control for details.

How do I process videos?

From URL or local path:

messages = [
    {
        "role": "user",
        "content": [
            {
                "type": "video",
                "video": "https://example.com/video.mp4",
                "fps": 1.0,  # Sample rate
                "total_pixels": 20480 * 32 * 32,  # Token budget
            },
            {"type": "text", "text": "Describe this video."},
        ],
    }
]

From image frames:

messages = [
    {
        "role": "user",
        "content": [
            {
                "type": "video",
                "video": [
                    "file:///path/to/frame1.jpg",
                    "file:///path/to/frame2.jpg",
                    "file:///path/to/frame3.jpg",
                ],
                "sample_fps": 1,
            },
            {"type": "text", "text": "Describe this video."},
        ],
    }
]

See Video Understanding for examples.

Deployment

How do I deploy for production?

Recommended: vLLM

# Install
pip install vllm>=0.11.0

# Serve
vllm serve Qwen/Qwen3-VL-8B-Instruct \
  --host 0.0.0.0 \
  --port 8000

# For large models with FP8
vllm serve Qwen/Qwen3-VL-235B-A22B-Instruct-FP8 \
  --tensor-parallel-size 8 \
  --mm-encoder-tp-mode data \
  --enable-expert-parallel

Alternative: SGLang

python -m sglang.launch_server \
  --model-path Qwen/Qwen3-VL-8B-Instruct \
  --host 0.0.0.0 \
  --port 8000 \
  --tp 4

See Deployment Guide for details.

Can I use the OpenAI API?

Yes! Both vLLM and the official Qwen API support OpenAI-compatible endpoints.

With vLLM:

from openai import OpenAI

client = OpenAI(
    api_key="EMPTY",
    base_url="http://localhost:8000/v1"
)

response = client.chat.completions.create(
    model="Qwen/Qwen3-VL-8B-Instruct",
    messages=[
        {
            "role": "user",
            "content": [
                {"type": "image_url", "image_url": {"url": "https://..."}},
                {"type": "text", "text": "Describe this image."}
            ]
        }
    ]
)

With official API:

client = OpenAI(
    api_key="YOUR_DASHSCOPE_API_KEY",
    base_url="https://dashscope.aliyuncs.com/compatible-mode/v1"
)

See API Reference.

How do I optimize inference speed?

1. Use vLLM or SGLang instead of transformers
2. Enable Flash Attention 2
   model = AutoModelForImageTextToText.from_pretrained(
       "Qwen/Qwen3-VL-8B-Instruct",
       attn_implementation="flash_attention_2"
   )
   
3. Use FP8 quantization (H100/H200)
4. Batch multiple requests
5. Reduce visual token budget for faster processing

See Deployment: Performance Optimization.

Fine-tuning

Can I fine-tune Qwen3-VL?

Yes! Fine-tuning code is available for Qwen2-VL and Qwen2.5-VL, which is compatible with Qwen3-VL.

Resources:

• Fine-tuning Code
• Released: April 8, 2025

See Fine-tuning Guide for details.

What data format is required for fine-tuning?

Qwen3-VL uses a conversational format with support for interleaved image/video/text:

{
  "messages": [
    {
      "role": "user",
      "content": [
        {"type": "image", "image": "path/to/image.jpg"},
        {"type": "text", "text": "What is in this image?"}
      ]
    },
    {
      "role": "assistant",
      "content": "This image shows..."
    }
  ]
}

See fine-tuning documentation for detailed format specifications.

Can I fine-tune on custom visual tasks?

Yes! Qwen3-VL can be fine-tuned for:

• Custom object detection/grounding
• Domain-specific OCR
• Specialized document understanding
• Custom visual reasoning tasks
• Agent behaviors

The model’s architecture supports various visual understanding tasks.

Technical Details

What’s the architecture?

Qwen3-VL introduces three key innovations:

1. Interleaved-MRoPE: Multi-resolution positional embeddings across time, width, and height
2. DeepStack: Multi-level ViT feature fusion for fine-grained details
3. Text-Timestamp Alignment: Precise temporal grounding beyond T-RoPE

Built on transformer architecture with vision encoder + language model.

See technical paper for details.

What is the patch size?

• Qwen3-VL: 16×16 pixels
• Qwen2.5-VL: 14×14 pixels

This affects visual token calculation and qwen-vl-utils usage:

images, videos = process_vision_info(messages, image_patch_size=16)

How are visual tokens calculated?

For images:

• Spatial compression: 32× (16×16 patches → merged)
• Tokens ≈ (height × width) / (32 × 32)

For videos:

• Spatial compression: 32×
• Temporal compression: 2×
• Tokens ≈ (frames × height × width) / (32 × 32 × 2)

Control via min_pixels, max_pixels, total_pixels parameters.

Community & Support

Where can I get help?

1. Documentation: You’re reading it!
2. GitHub Issues: Qwen3-VL Issues
3. Discord: Join server
4. WeChat: QR code
5. Troubleshooting: Common issues

How do I report a bug?

1. Check existing issues
2. Review troubleshooting guide
3. Create new issue with:
   • Model version and size
   • Environment (OS, Python, CUDA, library versions)
   • Minimal reproducible example
   • Error messages and logs

Where can I find examples?

Cookbooks (Jupyter notebooks):

• Omni Recognition
• Document Parsing
• 2D/3D Grounding
• OCR & Key Information Extraction
• Video Understanding
• Mobile/Computer Agent
• Visual Coding
• And more in the cookbooks directory

See Capabilities Overview for links.

License & Citation

What is the license?

Qwen3-VL models are released under permissive licenses allowing commercial use. Check individual model cards on HuggingFace for specific license details.

How do I cite Qwen3-VL?

@article{Qwen3-VL,
  title={Qwen3-VL Technical Report},
  author={Qwen Team},
  journal={arXiv preprint arXiv:2511.21631},
  year={2025}
}

Paper: https://arxiv.org/pdf/2511.21631

Related Resources

• Model Cards
• Benchmarks
• Troubleshooting
• Changelog
• Installation
• Quickstart