Undo-Ai is a Chrome browser extension designed to convert stiff, robotic text into natural, human-like writing. Users can paste a paragraph and select from various tones such as Casual, Professional, Academic, or Creative, receiving a refined version that maintains a genuine flow. The tool is particularly useful for improving blog drafts, emails, social media posts, product descriptions, cover letters, and scripts. It ensures privacy by processing all text on-device without sending data to servers, and it operates fully offline once the model is downloaded.

The extension offers a free tier, allowing users one rewrite per day of up to 1,500 characters in Casual and Professional tones. For more extensive use, a premium subscription unlocks unlimited rewrites, supports larger character limits, and provides access to all four tones with adjustable imperfection controls. The tool is built on the Gemini Nano AI technology and adheres to strict privacy standards, making it a reliable assistant for anyone looking to enhance their writing.