WebM

WebM is an open, royalty-free media file format developed by Google (based on Matroska container with VP8/VP9 video and Vorbis/Opus audio codecs) designed to provide small file sizes and efficient streaming for web video. It is optimized for HTML5 video delivery and supported by all major modern browsers.

WebM video optimization is evaluated through Google Lighthouse's performance audits and PageSpeed Insights, which track how media assets impact page load performance. Embedding WebM video with proper lazy loading and correct video schema markup improves both page speed scores and video rich result eligibility in Google Search.