AI Content Detector
Check articles, blog posts, essays, or marketing copy for AI-generated writing. Paste your content below to get an overall AI score and a breakdown of which passages look machine-written.
Use it to review drafts before publishing, audit submitted content, or sanity-check your own writing. Results are probabilistic signals (and detectors can flag human writing as AI), so combine them with your own judgment.
AI detection is not plagiarism checking
The two get bundled together, but they answer different questions. A plagiarism checker compares your text against existing documents — papers, websites, databases — to find passages copied without attribution. Its output is a similarity percentage and a list of matched sources.
An AI content detector has no source to match against: text ChatGPT generated a minute ago exists nowhere else, so similarity search can't catch it. Instead it analyzes the text's statistical grain — word-choice predictability, sentence-length uniformity, mechanical paragraph structure — and estimates the probability it was machine-generated. That's what this page does. The two checks don't replace each other, which is why institutions like universities typically run both (Turnitin, for example, reports a similarity score and a separate AI-writing indicator — does Turnitin check for AI?).
When to use it
Before submitting coursework — if your school screens with Turnitin or a similar tool, checking first shows you which sentences read as machine-written so you can rework them. Before publishing content — if a blog post or newsletter started as an AI draft, a pre-publish check shows which passages still read generic. When auditing submissions — editors and instructors use it to review outsourced or student writing, though a score should start a conversation, never end one.
In every case the sentence-level highlights matter more than the total score: adding specifics, numbers, and sources to flagged sentences improves the writing itself, not just the score (how accurate are detectors?).
Frequently asked questions
What's the difference between AI detection and plagiarism checking?+
Plagiarism checking compares your text against existing sources to find copied passages; AI detection analyzes the text's own statistical patterns to estimate whether a machine wrote it. One can't substitute for the other.
What counts as AI content?+
Any text produced by a generative model — full drafts, paragraphs, or AI-assisted rewrites. The detector estimates how much of your content shows AI writing patterns.
Can I check long articles?+
Yes. You can paste long content; very long inputs may take a little longer to analyze. For the most reliable score, submit at least 100 characters.
Will editing AI content lower the score?+
Often, yes. Substantive human edits that vary sentence length and structure tend to reduce AI signals — but heavy editing is no guarantee, and detectors remain imperfect.
Does it show which sources a text was copied from?+
No. This tool estimates AI generation, so there's no original document to point to. If you need source matching, pair it with a similarity-based plagiarism checker like Turnitin.
⚠️ Disclaimer: AI Killer results are probabilistic signals and are not 100% accurate. Detectors can flag human writing as AI, so do not use this as the sole basis for accusations of plagiarism, cheating, or academic misconduct.