Bulk Convert OPUS to FLAC Online — Lossless Compression

OPUS is a modern, open-source, royalty-free audio codec developed by Xiph.Org Foundation and IETF, standardized in RFC 6716 in September 2012. It was designed to replace both Vorbis (for music) and Speex (for voice), combining the best of both into a single codec. OPUS achieves exceptional quality at low bitrates—transparent quality at 128 kbps for music, and near-transparent voice at just 32 kbps. It supports bitrates from 6 kbps to 510 kbps and sample rates from 8 kHz to 48 kHz.

Learn more: Opus on Wikipedia

OPUS is the mandatory audio codec for WebRTC, making it the native format for video calls (Discord, Zoom, Google Meet, Teams) and voice messaging (WhatsApp, Telegram). It excels at both speech and music, adapting dynamically to content. OPUS files use the Ogg container (.opus extension) and play in all modern browsers (Chrome, Firefox, Edge, Safari 15+), VLC, and most media players from 2015 onward. For streaming, voice chat, podcasts, and any application where quality-per-bit matters, OPUS is the current state of the art.

FLAC (Free Lossless Audio Codec) is the open-source standard for lossless audio compression, developed by Xiph.Org Foundation and released in 2001. Unlike MP3 or AAC, FLAC compresses audio without discarding any data—the decoded output is bit-for-bit identical to the original. Typical compression ratios are 50-60%, meaning a 100 MB WAV becomes a 40-50 MB FLAC with zero quality loss.

Learn more: FLAC on Wikipedia

FLAC has become the format of choice for audiophiles, music archivists, and streaming services like Tidal, Qobuz, and (as of 2025) Spotify. It supports metadata, album art, and cue sheets for track indexing. The tradeoff is size and compatibility: FLAC files are 3-5x larger than equivalent MP3s, and some older devices lack native support. For permanent archives, FLAC preserves quality that can later be converted to any format without generation loss.