WebM to FLAC Converter — Free, Online, No Upload

WebM files use lossy compression — Opus or Vorbis audio — which is entirely appropriate for web streaming but a poor choice for archival purposes. If you want to preserve a recording for the long term, a lossy web format in a video container is not where that audio should live. Archivists and serious collectors want lossless formats in open containers.

FLAC is the archival audio standard. It is lossless, open-source, patent-free, and supported by every serious audio application: Plex, Jellyfin, Kodi, foobar2000, Audirvana, and all major DAWs. Unlike proprietary formats, FLAC will remain decodable by future software because its specification is entirely open. For recordings that matter, FLAC is the format you convert to once and never convert again.

Converting WebM to FLAC decodes the compressed audio and stores it in a lossless container. It is important to understand that FLAC cannot restore quality that Opus or Vorbis compression already removed — the FLAC output is a lossless copy of the already-compressed signal. What you gain is a permanent, open-format archive that is fully compatible with any audio tool, indexed correctly by media servers, and free from WebM's browser-centric container limitations. For high-bitrate Opus recordings, the difference from true lossless is minimal.

Typical sizes: WEBM 50–200 MB (1 minute 1080p); FLAC 20–40 MB (3-minute song).

FLAC will not restore detail the WEBM encoder removed, and the file gets bigger.