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Gemma 3

docs/source/en/model_doc/gemma3.md

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This model was released on 2025-03-25 and added to Hugging Face Transformers on 2025-03-12.

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Gemma 3

Gemma 3 is a multimodal model with pretrained and instruction-tuned variants, available in 1B, 13B, and 27B parameters. The architecture is mostly the same as the previous Gemma versions. The key differences are alternating 5 local sliding window self-attention layers for every global self-attention layer, support for a longer context length of 128K tokens, and a SigLip encoder that can "pan & scan" high-resolution images to prevent information from disappearing in high resolution images or images with non-square aspect ratios.

The instruction-tuned variant was post-trained with knowledge distillation and reinforcement learning.

You can find all the original Gemma 3 checkpoints under the Gemma 3 release.

[!TIP] Click on the Gemma 3 models in the right sidebar for more examples of how to apply Gemma to different vision and language tasks.

The example below demonstrates how to generate text based on an image with [Pipeline] or the [AutoModel] class.

<hfoptions id="usage"> <hfoption id="Pipeline">
python
from transformers import pipeline


pipeline = pipeline(
    task="image-text-to-text",
    model="google/gemma-3-4b-pt",
    device=0,
)
pipeline(
    "https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/pipeline-cat-chonk.jpeg",
    text="<start_of_image> What is shown in this image?"
)
</hfoption> <hfoption id="AutoModel">
python
from transformers import AutoProcessor, Gemma3ForConditionalGeneration


model = Gemma3ForConditionalGeneration.from_pretrained(
    "google/gemma-3-4b-it",
    device_map="auto",
    attn_implementation="sdpa"
)
processor = AutoProcessor.from_pretrained(
    "google/gemma-3-4b-it",
    padding_side="left"
)

messages = [
    {
        "role": "system",
        "content": [
            {"type": "text", "text": "You are a helpful assistant."}
        ]
    },
    {
        "role": "user", "content": [
            {"type": "image", "url": "https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/pipeline-cat-chonk.jpeg"},
            {"type": "text", "text": "What is shown in this image?"},
        ]
    },
]
inputs = processor.apply_chat_template(
    messages,
    tokenize=True,
    return_dict=True,
    return_tensors="pt",
    add_generation_prompt=True,
).to(model.device)

output = model.generate(**inputs, max_new_tokens=50, cache_implementation="static")
print(processor.decode(output[0], skip_special_tokens=True))
</hfoption> </hfoptions>

Quantization reduces the memory burden of large models by representing the weights in a lower precision. Refer to the Quantization overview for more available quantization backends.

The example below uses torchao to only quantize the weights to int4.

python
# pip install torchao
from transformers import AutoProcessor, Gemma3ForConditionalGeneration, TorchAoConfig


quantization_config = TorchAoConfig("int4_weight_only", group_size=128)
model = Gemma3ForConditionalGeneration.from_pretrained(
    "google/gemma-3-27b-it",
    device_map="auto",
    quantization_config=quantization_config
)
processor = AutoProcessor.from_pretrained(
    "google/gemma-3-27b-it",
    padding_side="left"
)

messages = [
    {
        "role": "system",
        "content": [
            {"type": "text", "text": "You are a helpful assistant."}
        ]
    },
    {
        "role": "user", "content": [
            {"type": "image", "url": "https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/pipeline-cat-chonk.jpeg"},
            {"type": "text", "text": "What is shown in this image?"},
        ]
    },
]
inputs = processor.apply_chat_template(
    messages,
    tokenize=True,
    return_dict=True,
    return_tensors="pt",
    add_generation_prompt=True,
).to(model.device)

output = model.generate(**inputs, max_new_tokens=50, cache_implementation="static")
print(processor.decode(output[0], skip_special_tokens=True))

Use the AttentionMaskVisualizer to better understand what tokens the model can and cannot attend to.

python
from transformers.utils.attention_visualizer import AttentionMaskVisualizer


visualizer = AttentionMaskVisualizer("google/gemma-3-4b-it")
visualizer("What is shown in this image?")
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Notes

  • Use [Gemma3ForConditionalGeneration] for image-and-text and image-only inputs.

  • Gemma 3 supports multiple input images, but make sure the images are correctly batched before passing them to the processor. Each batch should be a list of one or more images.

    py
    url_cow = "https://media.istockphoto.com/id/1192867753/photo/cow-in-berchida-beach-siniscola.jpg?s=612x612&w=0&k=20&c=v0hjjniwsMNfJSuKWZuIn8pssmD5h5bSN1peBd1CmH4="
    url_cat = "https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/pipeline-cat-chonk.jpeg"
    
    messages =[
        {
            "role": "system",
            "content": [
                {"type": "text", "text": "You are a helpful assistant."}
            ]
        },
        {
            "role": "user",
            "content": [
                {"type": "image", "url": url_cow},
                {"type": "image", "url": url_cat},
                {"type": "text", "text": "Which image is cuter?"},
            ]
        },
    ]
    
  • Text passed to the processor should have a <start_of_image> token wherever an image should be inserted.

  • The processor has its own [~ProcessorMixin.apply_chat_template] method to convert chat messages to model inputs.

  • By default, images aren't cropped and only the base image is forwarded to the model. In high resolution images or images with non-square aspect ratios, artifacts can result because the vision encoder uses a fixed resolution of 896x896. To prevent these artifacts and improve performance during inference, set do_pan_and_scan=True to crop the image into multiple smaller patches and concatenate them with the base image embedding. You can disable pan and scan for faster inference.

    diff
    inputs = processor.apply_chat_template(
        messages,
        tokenize=True,
        return_dict=True,
        return_tensors="pt",
        add_generation_prompt=True,
    +   do_pan_and_scan=True,
        ).to(model.device)
    
  • For Gemma-3 1B checkpoint trained in text-only mode, use [AutoModelForCausalLM] instead.

    py
    import torch
    from transformers import AutoModelForCausalLM, AutoTokenizer
    
    tokenizer = AutoTokenizer.from_pretrained(
        "google/gemma-3-1b-pt",
    )
    model = AutoModelForCausalLM.from_pretrained(
        "google/gemma-3-1b-pt",
        device_map="auto",
        attn_implementation="sdpa"
    )
    input_ids = tokenizer("Plants create energy through a process known as", return_tensors="pt").to(model.device)
    
    output = model.generate(**input_ids, cache_implementation="static")
    print(tokenizer.decode(output[0], skip_special_tokens=True))
    

Gemma3ImageProcessor

[[autodoc]] Gemma3ImageProcessor - preprocess

Gemma3ImageProcessorPil

[[autodoc]] Gemma3ImageProcessorPil - preprocess

Gemma3Processor

[[autodoc]] Gemma3Processor - call

Gemma3TextConfig

[[autodoc]] Gemma3TextConfig

Gemma3Config

[[autodoc]] Gemma3Config

Gemma3TextModel

[[autodoc]] Gemma3TextModel - forward

Gemma3Model

[[autodoc]] Gemma3Model

Gemma3ForCausalLM

[[autodoc]] Gemma3ForCausalLM - forward

Gemma3ForConditionalGeneration

[[autodoc]] Gemma3ForConditionalGeneration - forward - get_image_features

Gemma3ForSequenceClassification

[[autodoc]] Gemma3ForSequenceClassification - forward

Gemma3TextForSequenceClassification

[[autodoc]] Gemma3TextForSequenceClassification - forward