About Opus and AIFF

Opus is the newest codec here and the most efficient — it outperforms MP3, Vorbis, and AAC at low bitrates, which is why WhatsApp, Discord, and WebRTC all use it. Support is universal in browsers, patchier in older hardware.

AIFF is Apple's uncompressed audio format — the same raw PCM as WAV in a different wrapper, dating back to 1988. It's still the native interchange format for Logic Pro and much of the mac production world, and converts to WAV with zero quality change.

Converting Opus to AIFF produces a lossless file, though detail already discarded by Opus's compression can't be recovered — the new file is a faithful copy of the Opus, not of the original recording.

How the conversion works

This tool runs FFmpeg — the same engine behind most media software — compiled to WebAssembly, entirely in your browser. Your file is read locally, converted locally, and saved straight from memory; nothing is ever uploaded, which also means no queues and no server-side file size limits.

The converter itself is a one-time ~31 MB download on your first conversion, cached by the browser afterwards. Once it's loaded, everything works offline.