🇧🇷 pt-ai-detector

pt-ai-detector is a BERT-base model fine-tuned to decide whether a Portuguese sentence or paragraph was written by a human (label = 0) or generated by AI (label = 1).

Metric	Value
Train data	1 000 000 human + 1 000 000 AI
Balanced test set	1 954 190 (½ human, ½ AI)
Accuracy	≈ 99 %
F1 (macro)	≈ 0.99
Model size	434 M parameters (≈ 430 MB)

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📖 Quick usage

Try it live at detecting-ai.com – our team at Detecting-ai built this model and demo so you can instantly test any Portuguese text online.

from transformers import pipeline

clf = pipeline(
    "text-classification",
    model="Detecting-ai/pt-ai-detector",
    tokenizer="Detecting-ai/pt-ai-detector",
    device=0  # set -1 for CPU
)

text = "A inteligência artificial está transformando a educação."
print(clf(text))        # → [{'label': 'AI', 'score': 0.987}]

id	label
0	Human
1	AI

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🏋️‍♂️ Training details

• Base model: neuralmind/bert-base-portuguese-cased
• Epochs: 3 (fp16 on 1 × A100)
• Batch size: 32
• Optimizer/LR: AdamW 2 × 10⁻⁵
• Loss: Cross-entropy

Data sources

Corpus	Lines used	Notes
Human corpus (wiki40b-pt, oscar-pt, cc100-pt, europarl-pt, opus-books-pt)	1 M sampled	Diverse Portuguese web/news/books
AI corpus (Detecting-ai/ai_pt_corpus)	1 M	Generated with OpenAI models (various GPT-4 / GPT-3.5 variants); prompts cover essays, news, tweets, dialogs, paraphrases, T = 0.6–1.0

Datasets were balanced 1 : 1 and shuffled before training.

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🚦 Intended use

Detect AI-generated Portuguese text in essays, articles, chats, support tickets, etc.

Limitations

• Not trained on code or non-Portuguese language.
• Accuracy may drop on texts < 10 tokens or heavily paraphrased AI.
• Commercial use is disallowed (CC-BY-NC-4.0).

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⚠️ Future work

• Evaluate on adversarial paraphrases.
• Distill/quantize for edge deployment.
• Extend to multilingual detection.

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📜 Citation

@misc{abdurazzoqov2025ptaidetector,
  title   = {pt-ai-detector: Detecting AI-generated Portuguese Text},
  author  = {Abdulla Abdurazzoqov},
  year    = {2025},
  howpublished = {Hugging Face hub},
  url     = {https://huggingface.co/Detecting-ai/pt-ai-detector}
}

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💬 License

Creative Commons CC-BY-NC-4.0 — free for research & personal use; commercial use requires written permission.