YTGloss

Gloss (previously known as YTGloss) is a free AI-powered browser extension designed to enhance learning from YouTube videos by providing real-time, contextual definitions. It works by detecting unfamiliar words, concepts, or abbreviations as they appear in a video and displaying an explanation in the top-right corner of the screen, eliminating the need to pause and search manually. The extension claims to understand the video's subject matter to deliver context-aware explanations (e.g., distinguishing a cell in biology from one in programming). Users can activate a learning mode on demand via keyboard shortcut or the extension menu, allowing them to switch between focused and casual viewing.

The tool is available for Chrome and Edge browsers and appears to support any YouTube video. It offers a free tier with approximately 4 hours of video analysis per month, along with paid plans (Curious at $6/month for 10 hours, Serious at $18/month for 30 hours, and Ambitious at $35/month for 90 hours) that include email or priority support and early access features. All paid plans come with a 7-day money-back guarantee. Based on available information, users can upgrade directly through the extension's side panel or account settings.

Gloss positions itself as a learning aid for students, professionals, and self-learners who watch educational content on YouTube. User testimonials highlight its usefulness in retaining information and reducing interruptions. The extension focuses solely on YouTube and does not appear to support other video platforms. It requires an internet connection to analyze video content and deliver real-time explanations, and its accuracy depends on the underlying AI model and the quality of the video's audio or captions.