GPTrue or False

GPTrue or False is a browser extension available on both Chrome and Firefox that displays the likelihood that a portion of selected text was generated by OpenAI’s GPT-2 model.

How it Works

Having selected a portion of text comprising of at least 50 words, the user is able to prompt the extension for an evaluation of the selected text. The extension takes the selected text and passes it via an HTTP GET request to this webpage hosted publicly by Hugging Face (check them out!). The webpage is an interface to OpenAI’s GPT-2 Detector model, which outputs the likelihood that inputted text was generated by GPT-2.

The response from the Hugging Face webpage is received by the extension, parsed and neatly displayed under the selected text. See this example demo provided by Blair Hudson on Twitter:

Ok but how does it actually work

The underlying mechanisms of GPT-2 are bit out of scope for a simple project page like this one. I would like to write a blogpost one day going more into depth about what’s going on behind the scenes (i.e. beyond the frontend browser extension stuff). Patience please!

In the press

The project received a surprising amount of attention, probably thanks to the initial reaction from Tesla’s director of AI, Andrej Karpathy and JavaScript creator Brendan Eich who both tweeted about it:

The extension was later featured on a number of tech news websites including DigitalTrends, LifeHacker, TechTheLead, among others.


The project is of course open-source, with the code available on GitHub. Feel free to contribute!