Grammarly is a free site that allows you to upload a file or copy and paste text. It will also check for spelling and grammatical errors.
Search for suspicious text in Google using quotation marks for an exact match.
Strange formatting i.e. different text fonts and colors could be a sign that student has copied/pasted from the web.
Multiple citation formats used in the same paper can be a sign of copying from a variety of sources.
Look for inconsistencies in writing style.
Unfortunately, the short answer is no -- we cannot recommend any software to reliably check for the use of AI because there is none that works well enough. Numerous articles have stated that AI detectors give too many false positives on work that students have written themselves. AI detectors are also easy to "fool" by making simple changes to AI-generated text. Even OpenAI, the creators of ChatGPT, say that AI detectors don't work (see "Do AI detectors work?" in this article for more details).
If you are an instructor who suspects that a student has used AI for academic work in a non-approved way, consider following the steps suggested on this page from the Center for Teaching Excellence at the University of Kansas, in the section that begins, "So how should instructors use the AI detection tool? Instead of making quick judgments ... take a few more steps to gather information."
Visit our Artificial Intelligence in Teaching & Learning guide to learn more.
MyBib: Fully automated bibliography maker builds works cited/references pages in several different citation styles.
NOTE: STCC Library's Citing Sources Guide is also helpful when working the MLA, APA or AMA formats.