A Practical Examination of AI-Generated Text Detectors for Large Language Models

Brian Tufts, Xuandong Zhao, Lei Li


Abstract
The proliferation of large language models has raised growing concerns about their misuse, particularly in cases where AI-generated text is falsely attributed to human authors. Machine-generated content detectors claim to effectively identify such text under various conditions and from any language model. This paper critically evaluates these claims by assessing several popular detectors (RADAR, Wild, T5Sentinel, Fast-DetectGPT, PHD, LogRank, Binoculars) on a range of domains, datasets, and models that these detectors have not previously encountered. We employ various prompting strategies to simulate practical adversarial attacks, demonstrating that even moderate efforts can significantly evade detection. We emphasize the importance of the true positive rate at a specific false positive rate (TPR@FPR) metric and demonstrate that these detectors perform poorly in certain settings, with TPR@.01 as low as 0%. Our findings suggest that both trained and zero-shot detectors struggle to maintain high sensitivity while achieving a reasonable true positive rate.
Anthology ID:
2025.findings-naacl.271
Volume:
Findings of the Association for Computational Linguistics: NAACL 2025
Month:
April
Year:
2025
Address:
Albuquerque, New Mexico
Editors:
Luis Chiruzzo, Alan Ritter, Lu Wang
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
4824–4841
Language:
URL:
https://preview.aclanthology.org/fix-sig-urls/2025.findings-naacl.271/
DOI:
Bibkey:
Cite (ACL):
Brian Tufts, Xuandong Zhao, and Lei Li. 2025. A Practical Examination of AI-Generated Text Detectors for Large Language Models. In Findings of the Association for Computational Linguistics: NAACL 2025, pages 4824–4841, Albuquerque, New Mexico. Association for Computational Linguistics.
Cite (Informal):
A Practical Examination of AI-Generated Text Detectors for Large Language Models (Tufts et al., Findings 2025)
Copy Citation:
PDF:
https://preview.aclanthology.org/fix-sig-urls/2025.findings-naacl.271.pdf