Most video downloaders either make you paste a URL into a website, or they only grab the obvious tag on the page. Videoff lives in your browser and goes deeper: Deep detection: scans shadow DOM, iframes, and intercepts network requests to catch HLS/DASH manifests that other tools miss entirely. Firefox Android support: same extension works on desktop and mobile (most tools ignore mobile entirely). Adapter system: site-specific support (YouTube, Vimeo, X, TikTok…) that's easy to extend.