Opus is a modern, open-source, royalty-free audio codec standardized by the IETF in 2012. It's designed to handle the full range of audio applications in a single codec: excellent voice quality at 8-24 kbps (better than MP3 at the same bitrate), good music quality at 32-128 kbps, and transparent audio at 96-192 kbps. This versatility makes it the codec of choice for real-time communication applications.
Opus is used by Discord for voice chat, WhatsApp for voice messages, Zoom for audio, WebRTC (the technology behind browser-based video calls), Spotify for mobile streaming, and YouTube for some audio streams. Its low-latency design (as low as 2.5ms algorithmic delay) makes it suitable for real-time applications where MP3's encoding delay would be unacceptable.
For podcast distribution and general sharing, MP3 or AAC remain more compatible. For web applications and services, Opus in OGG container is supported by Chrome and Firefox. FileCurve's audio tools output MP3 for maximum compatibility, but future versions may add Opus support for web-optimized delivery.