Convert Opus Audio Codec (.opus) to Apple Lossless Audio Codec (.alac) online for free. Fast, secure audio conversion with no watermarks or registration.
Conversion settings — add a file to adjust
Upload your .opus file by dragging it into the upload area or clicking to browse.
Choose your output settings. The default settings work great for most files.
Click Convert and download your .m4a file when it's ready.
Apple Lossless Audio Codec (ALAC) provides bit-perfect audio compression natively supported across every Apple device — Mac, iPhone, iPad, Apple TV, Apple Watch, and HomePod. Converting Opus recordings to ALAC creates a losslessly compressed archive that integrates with Apple Music, iCloud Music Library, and AirPlay without any third-party software. ALAC typically compresses to 50-60% of the equivalent uncompressed size while preserving identical PCM data upon decoding.
Opus, created by Xiph.org and the IETF, is the standard voice codec for Discord, Telegram, and WebRTC browsers. While Opus achieves remarkable quality at low bitrates, it is a lossy codec that Apple's native apps do not support. By converting to ALAC, you preserve the maximum possible quality from the Opus decode in a format that Apple's ecosystem handles natively everywhere.
Apple Music and iTunes only support ALAC for lossless audio — FLAC, despite being more universally available, requires third-party apps on iOS and macOS for playback. If you want to store decoded Opus recordings in the highest quality format that syncs across your Apple devices via iCloud, ALAC is the only option. The lossless compression means you can reconvert to any other format in the future without additional quality degradation.
ALAC is also the format Apple uses for its own Lossless tier on Apple Music, lending it credibility as a long-term archival format. For anyone maintaining an Apple-centric audio library, converting Opus recordings to ALAC before importing into Apple Music ensures they are treated as lossless content and benefit from iCloud syncing to all connected devices.
FFmpeg decodes the Opus audio using libopus (48 kHz internal rate), then encodes it with the ALAC codec into an M4A (MPEG-4) container. The output uses 16-bit depth at 44.1 kHz by default, though 24-bit/48 kHz is available. ALAC's lossless compression achieves roughly 40-60% of the uncompressed PCM size, depending on audio content. Speech content compresses better than music due to lower entropy. The M4A container supports full metadata (title, artist, album, artwork).
ALAC is mathematically lossless — the decoded PCM output is bit-for-bit identical to the input PCM. The only quality limitation comes from the original Opus encoding, which is lossy. Converting Opus to ALAC preserves the full decoded Opus audio without any additional degradation. This is the highest-quality archive possible from an Opus source within the Apple ecosystem.
| Device | Opus | ALAC |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Native |
| iPhone/iPad | Partial | Native |
| Android | Partial | Partial |
| Linux | Partial | Partial |
| Web Browser | No |
Resolution: N/A
Bitrate: 320 kbps
OGG Vorbis preferred
Resolution: N/A
Bitrate: 256 kbps
AAC format required
Resolution: N/A
Bitrate: 128 kbps
Lossless FLAC/WAV for best quality
Resolution: N/A
Bitrate: 128 kbps
MP3 mono for spoken word
Opus to ALAC is the optimal conversion for Apple users who want the highest possible quality from their Opus recordings. ALAC's lossless compression preserves every detail of the decoded audio while integrating natively with Apple Music, iCloud, and AirPlay — a combination no other format achieves.
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| No |
| Funktion | Opus | ALAC |
|---|---|---|
| Fulde navn | Opus Audio Codec | Apple Lossless Audio Codec |
| Filendelse | .opus | .m4a |
| Bedst til | Low latency | Lossless |