01In plain English
An AI detector reads a piece of writing and gives a score for how likely it is that an AI model produced it. It works from patterns in word choice and sentence structure. The score is an estimate, not proof, and detectors can be wrong in both directions.
02Why it matters when you are choosing
Schools, publishers and editors use detectors to screen work, and writers use them to see how their text might be read. Because false flags happen, treating a score as a verdict can treat real writers unfairly.
03What to check
Check whether the vendor states how often it flags human writing by mistake, and test it on text you know was written by a person. Use the result as a prompt to look closer, not as the final answer.
04The tools
6 of the 19 tools we checked include an AI detector. Each one is checked against the vendor's own pages. A tool missing from this list may not have been checked yet, which is not the same as a no.
QuillBot
Grammarly
Paperpal
Smodin
GPTZero
