transformers/docs/source/en/model_doc/modernbert.md

ModernBERT

ModernBERT is a modernized version of [BERT] trained on 2T tokens. It brings many improvements to the original architecture such as rotary positional embeddings to support sequences of up to 8192 tokens, unpadding to avoid wasting compute on padding tokens, GeGLU layers, and alternating attention.

You can find all the original ModernBERT checkpoints under the ModernBERT collection.

Tip

Click on the ModernBERT models in the right sidebar for more examples of how to apply ModernBERT to different language tasks.

The example below demonstrates how to predict the [MASK] token with [Pipeline], [AutoModel], and from the command line.

import torch
from transformers import pipeline

pipeline = pipeline(
    task="fill-mask",
    model="answerdotai/ModernBERT-base",
    torch_dtype=torch.float16,
    device=0
)
pipeline("Plants create [MASK] through a process known as photosynthesis.")

import torch
from transformers import AutoModelForMaskedLM, AutoTokenizer

tokenizer = AutoTokenizer.from_pretrained(
    "answerdotai/ModernBERT-base",
)
model = AutoModelForMaskedLM.from_pretrained(
    "answerdotai/ModernBERT-base",
    torch_dtype=torch.float16,
    device_map="auto",
    attn_implementation="sdpa"
)
inputs = tokenizer("Plants create [MASK] through a process known as photosynthesis.", return_tensors="pt").to("cuda")

with torch.no_grad():
    outputs = model(**inputs)
    predictions = outputs.logits

masked_index = torch.where(inputs['input_ids'] == tokenizer.mask_token_id)[1]
predicted_token_id = predictions[0, masked_index].argmax(dim=-1)
predicted_token = tokenizer.decode(predicted_token_id)

print(f"The predicted token is: {predicted_token}")

echo -e "Plants create [MASK] through a process known as photosynthesis." | transformers run --task fill-mask --model answerdotai/ModernBERT-base --device 0

ModernBertConfig

autodoc ModernBertConfig

ModernBertModel

autodoc ModernBertModel - forward

ModernBertForMaskedLM

autodoc ModernBertForMaskedLM - forward

ModernBertForSequenceClassification

autodoc ModernBertForSequenceClassification - forward

ModernBertForTokenClassification

autodoc ModernBertForTokenClassification - forward

ModernBertForQuestionAnswering

autodoc ModernBertForQuestionAnswering - forward

Usage tips

The ModernBert model can be fine-tuned using the HuggingFace Transformers library with its official script for question-answering tasks.