AI content detection refers to the methods and tools used to identify whether a piece of text was generated, wholly or in part, by a large language model rather than written by a human. Classifiers such as GPTZero, Originality.ai, and Turnitin’s detection layer attempt to identify statistical patterns—such as low perplexity, high predictability, and uniform sentence structure—that are characteristic of LLM output. From an SEO perspective, the topic is significant because Google has stated that its quality systems target unhelpful, low-quality AI-generated content rather than AI content per se, and because publishers, academic institutions, and content marketplaces increasingly screen submissions for machine-generated text. Detection accuracy remains a contested area: classifiers produce both false positives and false negatives, and paraphrasing tools can be used to evade detection. As of 2024, no AI detection method is considered definitively reliable, and Google has advised that the origin of content matters less than whether it demonstrates expertise, experience, authoritativeness, and trustworthiness.