Convert MPEG-4 Part 14 (.mp4) to Apple Lossless Audio Codec (.alac) online for free. Fast, secure video conversion with no watermarks or registration.
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Choose your output settings. The default settings work great for most files.
Click Convert and download your .m4a file when it's ready.
MP4 to ALAC conversion extracts audio from an MPEG-4 video and encodes it using Apple Lossless Audio Codec. ALAC compresses audio without discarding any data — every sample is mathematically identical when decoded. Apple open-sourced ALAC in 2011, and it is the lossless format natively supported by iTunes, Apple Music, iPhone, iPad, Mac, Apple TV, and HomePod.
Our converter decodes the audio from your MP4 and re-encodes it with the ALAC codec, producing an .m4a file (ALAC uses the M4A container). The result is a lossless audio file at roughly 50-60% of the uncompressed size, fully compatible with the Apple ecosystem.
ALAC fills the gap between lossy AAC and massive uncompressed AIFF. If you want the best possible audio from your video content and you live in the Apple ecosystem, ALAC delivers bit-perfect quality at half the file size of uncompressed formats. Apple Music supports ALAC natively for its Lossless tier, so converting your video audio to ALAC ensures it integrates with your existing Apple library. AirPlay 2 transmits ALAC without additional transcoding, preserving quality through your HomePod or AirPlay speakers.
FFmpeg decodes the MP4 audio stream and re-encodes using the ALAC encoder (-c:a alac). The output is muxed into an M4A container (MPEG-4 audio). ALAC preserves the original sample rate and bit depth. Typical compression ratios are 40-60% of the PCM equivalent. The codec uses linear prediction and entropy coding similar to FLAC but with Apple-specific framing. Unlike AAC, ALAC decoding produces bit-identical output to the original PCM input.
ALAC is mathematically lossless — the decoded output is bit-for-bit identical to the PCM audio that went in. However, since your MP4 source likely contains lossy AAC audio, the ALAC output preserves the AAC decode perfectly but cannot recover information lost during original AAC encoding. The practical benefit is preventing any further generational loss during editing or format conversion.
| Device | MP4 | ALAC |
|---|---|---|
| Windows PC | Native | Partial |
| macOS | Native | Native |
| iPhone/iPad | Native | Native |
| Android | Native | Partial |
| Linux | Partial | Partial |
| Web Browser | Native |
Resolution: 1920x1080
Bitrate: 8-12 Mbps
H.264 recommended for fast processing
Resolution: 1080x1080
Bitrate: 3.5 Mbps
Square or 9:16 for Reels
Resolution: 1080x1920
Bitrate: 4 Mbps
9:16 vertical, under 60s ideal
Resolution: 1280x720
Bitrate: 5 Mbps
Under 140s, 512MB max
Resolution: 960x540
Bitrate: 2 Mbps
16MB limit for standard, 64MB for document
Resolution: 1280x720
Bitrate: 4 Mbps
MP4 to ALAC is the ideal conversion for Apple users who want lossless audio from their video files. The files are significantly smaller than AIFF or WAV while preserving perfect audio fidelity for the Apple ecosystem.
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Mọi trình duyệt, mọi thiết bị
| Tính năng | MP4 | ALAC |
|---|---|---|
| Tên đầy đủ | MPEG-4 Part 14 | Apple Lossless Audio Codec |
| Phần mở rộng | .mp4 | .m4a |
| Phù hợp nhất cho | Universal compatibility | Lossless |