Horizon AI Signal

Detect AI-generated text on search results and web pages — a private, on-device heuristic.

AI Signal is a heuristic "smell test" for AI-written text. On Google, DuckDuckGo, and Brave it shows a badge on each search result with an estimated AI score, and can auto-hide high-scoring results. An optional Page Detector adds a floating score to article pages you visit. Every analysis runs entirely on your device on the title and snippet already shown on the page. No page content is uploaded anywhere. AI Signal is honest about its limits: it is a statistical estimate, not a definitive detector, and can produce false positives and false negatives. Single purpose: Detects AI-generated text on search results and web pages.