WebM Video (WEBM) packages VP8/VP9 or AV1 video with Vorbis/Opus audio in a royalty-free container designed for web streaming. Flash Video (FLV) packages Sorenson Spark or VP6 video in Adobe's Flash container, now largely obsolete following the end of Flash Player support. This conversion changes the file's encoding, compression method, and supported feature set. Metadata such as creation date and embedded colour profiles is preserved where the target format supports it. The result is a standard FLV file readable by any compatible application. 1converter handles WEBM-to-FLV conversion server-side: files are uploaded over HTTPS, processed on isolated cloud infrastructure, and the converted output is available for download for 24 hours before automatic deletion. No account is required for standard conversions.