Thursday, 11:40 pm
ai content detection

GLTR: A Powerful Tool for Detecting Automatically Generated Text

In an age where large language models are capable of generating realistic text that can be mistaken for human writing, it is crucial to have tools that can detect automatically generated content. GLTR (short for Giant Language Model Test Room) is a groundbreaking tool developed by the collaboration of the MIT-IBM Watson AI Lab and HarvardNLP to tackle this challenge. By utilizing state-of-the-art language models and innovative forensic techniques, GLTR can provide a visual analysis of the likelihood of a text being generated by an automatic system.

Understanding Language Models and Text Generation

Before delving into the features and use cases of GLTR, let’s first explore what language models are and how they generate text. In recent years, the natural language processing community has witnessed the development of increasingly large language models. These models are trained to predict the next word based on an input context, allowing them to generate text one word at a time. The power of these models lies in their ability to generate text that is indistinguishable from human-written text to non-expert readers.

Large language models achieve this by accurately estimating the distribution of words that are likely to follow in a given context. However, this also opens up opportunities for malicious actors to use these models for generating fake reviews, comments, or news articles to manipulate public opinion. To counteract this, forensic techniques are needed to detect automatically generated text.

The Power of GLTR: Detecting Automatically Generated Text

GLTR is a visually forensic tool designed to detect text that has been automatically generated by large language models. It leverages the GPT-2 117M language model from OpenAI, one of the largest publicly available models, to analyze the predictions made by the model at each position in the input text. By computing the ranking of each predicted word, GLTR can overlay a color-coded mask over the text to indicate the likelihood of each word being generated by the model.

When using GLTR, words that rank within the top 10 are highlighted in green, words in the top 100 are highlighted in yellow, words in the top 1,000 are highlighted in red, and the rest of the words are highlighted in purple. This visual representation allows users to easily assess the likelihood of a text being automatically generated. Additionally, by hovering over a word, GLTR provides the top 5 predicted words, their associated probabilities, and the position of the following word, allowing users to gain deeper insights into the model’s predictions.

Key Features of GLTR

  • Visual analysis of the likelihood of text being automatically generated
  • Integration with the GPT-2 117M language model for accurate predictions
  • Color-coded highlighting of word rankings for easy interpretation
  • Hover-over functionality for detailed word predictions and probabilities

Use Cases for GLTR

GLTR has a wide range of applications across various domains. Some of its use cases include:

  • Content moderation: Companies can use GLTR to detect automatically generated fake reviews, comments, or news articles to ensure the authenticity of their platforms.
  • Journalism: Journalists can utilize GLTR to verify the source of text and identify any potential automated content generation in news articles.
  • Academic research: GLTR can be used to detect automatically generated text in academic papers, ensuring the integrity of research publications.
  • Educational purposes: GLTR can serve as an educational tool to teach students about language models and the dangers and possibilities of text generation.

With these use cases in mind, GLTR empowers users to make informed decisions about the authenticity of text and combat the potential misuse of language models for generating misleading content.

Alternatives to GLTR

While GLTR offers a unique and powerful solution for detecting automatically generated text, there are alternative tools and approaches available in the field of natural language processing. Some popular alternatives include:

  1. GROVER: Developed by the Allen Institute for Artificial Intelligence, GROVER is a tool that aims to detect and generate fake news. It leverages transformer-based language models to provide insights into the likelihood of a given text being generated by a machine.
  2. DeepMoji: DeepMoji is a model developed by MIT researchers for sentiment analysis in text. Although it has different use cases compared to GLTR, it showcases the power of language models in understanding and analyzing text.
  3. OpenAI’s Inference API: OpenAI offers an inference API that enables developers to generate text using powerful language models like GPT-3. This API can be used for various applications and provides an alternative approach to text generation.

It’s essential to explore these alternatives and choose the tool that best fits your specific requirements and use cases.

Pricing and Availability

GLTR is an open-source tool that is publicly deployed and available for use. It can be accessed through the live demo on the GLTR website. The tool is continuously being improved and developed by the research teams at the MIT-IBM Watson AI Lab and HarvardNLP, ensuring its relevance and accuracy in detecting automatically generated text.


In a world where the line between human and machine-generated text is becoming increasingly blurred, tools like GLTR are vital for detecting automatically generated content. By leveraging advanced language models and innovative visualization techniques, GLTR provides users with a powerful means of assessing the authenticity of text. Whether it’s for content moderation, journalism, academic research, or educational purposes, GLTR offers a valuable tool in the fight against misleading and manipulated text.

So, if you find yourself questioning the authenticity of a piece of text, put GLTR to the test and uncover the truth behind the words. Let GLTR be your forensic partner in unraveling the mysteries of automatically generated text.

Check out the live demo of GLTR today and experience the power of visual forensic analysis in detecting automatically generated text.

Find GLTR on Twitter as @hen_str, @sebgehr, and @harvardnlp and let them know about your experience. For more information, you can also reach out to them via email at

Gehermann, S., Strobelt, H., & Rush, A. (2019). GLTR: Statistical Detection and Visualization of Generated Text. Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics: System Demonstrations, 111-116. DOI: 10.18653/v1/P19-3019.

Note: The content in this article is based on the provided description of GLTR and does not reflect personal testing or experiences.


Copy Badge to Embed on Your Site

Leave feedback about this

  • Quality
  • Price
  • Service


Add Field


Add Field