Attentions not returned from transformers ViT model when using output_attentions=True

I’m using this code snippet from the docs of HuggingFace ViT classification model - with one addition: I’m using the output_attentions=True parameter. Nevertheless, no attentions are returned.

from transformers import ViTFeatureExtractor, ViTForImageClassification
from PIL import Image
import requests

url = ''
image =, stream=True).raw)

feature_extractor = ViTFeatureExtractor.from_pretrained('google/vit-base-patch16-224')
model = ViTForImageClassification.from_pretrained('google/vit-base-patch16-224',output_attentions=True)

inputs = feature_extractor(images=image, return_tensors="pt")
outputs = model(**inputs)
logits = outputs.logits

# --> this should print the attentions

# model predicts one of the 1000 ImageNet classes
predicted_class_idx = logits.argmax(-1).item()
print("Predicted class:", model.config.id2label[predicted_class_idx])

The output of print(output.attentions) is:

attentions=(None, None, None, None, None, None, None, None, None, None, None, None)

What am I doing wrong, and how can I get the attentions values?


You need to pass the flag to the forward of the model:

outputs = model(**inputs, output_attentions=True)

Still doesn’t work, but it seems to be related to version 4.41, as mentioned in this Github issue:

I’m still not sure how to resolve it, though

solved by adding attn_implementation="eager":

model = ViTForImageClassification.from_pretrained("google/vit-base-patch16-224", attn_implementation="eager")