Coda One is a small set of AI writing tools built around one loop: check a draft, then fix what the check finds. The AI Detector is free with no signup, and it marks the specific phrases that read as machine-written instead of just giving a score. Alongside it are an AI Humanizer with nine writing modes, an AI Rewriter and a Grammar Checker, available in the browser and in a Chrome extension. The writing tools are free for a few runs a day, with paid plans from $9.99 a month. Built by a small independent team in London.
Coda One is built around one loop: check a draft, then fix what the check finds. Students, writers and teams increasingly draft with AI help, and they want to see which parts still read as machine-written. So we made the AI Detector free with no daily limit and no signup, and had it mark the specific phrases that read as machine-written instead of just giving a score. Detection is evidence, not proof, so the fix matters as much as the check: the AI Humanizer, AI Rewriter and Grammar Checker sit right next to the detector, in the browser and in a Chrome extension. We're a small independent team in London, and Coda One launched in February 2026.