AI Scanner.io

AI Scanner.io is a content detector tool. AI Scanner is a free web-based AI content detector that returns an AI score and a sentence-by-sentence report for pasted or uploaded text. It needs no account, handles up to 3,000 words per scan, and targets students, teachers and researchers.

AI Scanner is a browser-based AI text detector that estimates how much of a passage was written by a language model. Users paste text or upload a document (doc, txt or docx, up to 10MB), run the scan, and receive an AI score alongside a sentence-by-sentence report that marks the lines most likely to come from an AI tool. The score represents the share of the text judged to be machine-generated, whether or not a person edited it afterward. The audience is mostly academic. The homepage speaks directly to high school, college and graduate students, ESL writers worried about false accusations, teachers who suspect a submission, and researchers preparing papers for journals. Because results are highlighted at the sentence level, a writer can see exactly which lines to rework, and a reviewer can see that a mixed text is not a clear-cut case. The site is candid that no detector is perfect, and it notes that formulaic human writing can be flagged, as can AI-assisted drafts. In practice the tool needs no account. Each scan is capped at 3,000 words, and longer documents can be split into chunks of similar size. The developers say texts are encrypted in transit and at rest, used only for the analysis, and not kept afterward. Detection is based on how predictable the writing is: repetitive vocabulary, uniform syntax, generic claims and stock phrases weigh toward an AI verdict. It is meant to cover output from ChatGPT, Claude, Gemini, Grok, DeepSeek and Llama, including paraphrased or humanized text, though it does not identify which model produced a passage. The company claims 99% accuracy from its own benchmark, and also warns that passages under 300 words may be analyzed poorly. Among alternatives, it competes with paid classroom detectors and other free checkers by removing the paywall, the registration step and per-day limits. It does not check for plagiarism, so anyone who needs originality matching must use a separate tool. A small blog explains how detection works and how to use it on essays.