At first glance GPTZero works much like the other AI detection tools that I've tried in the last couple of weeks. To use it you paste a block of writing (at least 250 characters) into the text field and GPTZero tells you the likelihood of that text being written by AI.
There are some features of GPTZero that make it a bit different from some of the other AI detection tools that I've tried. First, in addition to accepting text that you copy and paste into it, GPTZero lets you upload PDFs, Word docs, and TXT files to analyze them. Second, GPTZero will highlight for you the parts of an article that it determines to have a high likelihood of being written by an AI tool. Third, GPTZero provides a perplexity score and a burstiness score to illustrate how it was determined that a document was or was not written by an AI tool.