Convert RAW Audio to ALAC — Free Online Converter
Convert Raw PCM Audio (.raw-audio) to Apple Lossless Audio Codec (.alac) online for free. Fast, secure audio conversion with no watermarks or registra...
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How to Convert
Upload your .raw 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.
About RAW Audio to ALAC Conversion
Raw PCM audio is the digital audio equivalent of raw binary data — a continuous stream of sample values with no container structure, no header, and no embedded metadata. Every aspect of the audio format must be known in advance: sample rate, sample depth, endianness, and channel count. This format is produced by low-level audio capture APIs, embedded microcontrollers with I2S interfaces, FPGA audio pipelines, and scientific instruments that write samples directly to storage.
ALAC (Apple Lossless Audio Codec) is Apple's lossless compression format, reducing file sizes by 40-60% without altering a single sample. ALAC files are natively supported across the entire Apple ecosystem — iPhone, iPad, Mac, Apple TV, HomePod, Apple Music, iTunes, AirPlay — making it the preferred lossless format for users who live within Apple's hardware and software world.
Why Convert RAW Audio to ALAC?
Raw PCM consumes enormous storage — a 3-minute stereo recording at 44.1 kHz / 16-bit is 31.5 MB, and at 96 kHz / 24-bit it balloons to 103 MB. This data has no header, so it cannot be played, tagged, or cataloged by any media library. It is functionally dead storage until wrapped in a proper container.
ALAC provides 40-60% lossless compression, cutting that 31.5 MB file to roughly 15-19 MB while preserving every single sample bit-for-bit. The M4A container adds metadata support, chapter markers, and artwork embedding. For anyone operating within the Apple ecosystem who needs lossless audio from raw hardware captures, ALAC is the most natural and space-efficient destination.
Common Use Cases
- Compressing raw audio hardware test recordings for lossless archival in an Apple Music library
- Converting I2S microcontroller audio captures into a format playable on iPhone and iPad
- Creating space-efficient lossless backups of raw scientific acoustic recordings
- Packaging raw DAC evaluation recordings for distribution to Apple-ecosystem audio reviewers
- Building an Apple-compatible lossless music library from raw vinyl digitization captures
How It Works
FFmpeg reads the headerless raw file using explicit parameters: `-f s16le -ar 44100 -ac 2` for 16-bit signed little-endian stereo at 44.1 kHz. The raw PCM is decoded into FFmpeg's internal sample format, then encoded using the ALAC encoder (`-c:a alac`). ALAC supports 16-bit and 24-bit integer samples and sample rates up to 384 kHz. The encoded stream is wrapped in an M4A (MPEG-4 Audio) container with proper atom structure for Apple device compatibility.
Quality & Performance
ALAC is mathematically lossless — after decoding, the output samples are identical to the input samples, bit for bit. Converting from raw PCM to ALAC preserves 100% of the audio information while achieving 40-60% file size reduction through predictive coding and entropy compression. The quality is limited only by the accuracy of the input parameters specified during conversion; incorrect parameters will produce a lossless encoding of misinterpreted data.
Device Compatibility
| Device | RAW Audio | ALAC |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Native |
| iPhone/iPad | Partial | Native |
| Android | Partial | Partial |
| Linux | Partial | Partial |
| Web Browser | No | No |
Recommended Settings by Platform
Spotify
Resolution: N/A
Bitrate: 320 kbps
OGG Vorbis preferred
Apple Music
Resolution: N/A
Bitrate: 256 kbps
AAC format required
SoundCloud
Resolution: N/A
Bitrate: 128 kbps
Lossless FLAC/WAV for best quality
Podcast
Resolution: N/A
Bitrate: 128 kbps
MP3 mono for spoken word
Tips for Best Results
- 1ALAC preserves the full bit depth of your raw source — always use the correct input bit depth flag to avoid unnecessary quantization
- 2For 24-bit raw files from professional audio interfaces, specify `-f s24le` (or `s24be` for big-endian hardware) to maintain full dynamic range
- 3The M4A container supports chapter markers — useful for long-form recordings that benefit from navigation points
- 4Compare file sizes between ALAC and FLAC for your specific audio content — FLAC sometimes achieves slightly better compression ratios
- 5Batch convert entire directories of raw test captures using FFmpeg's glob input pattern for efficient processing
Raw audio to ALAC conversion applies Apple's lossless compression to pristine uncompressed samples, delivering substantial space savings and universal Apple ecosystem playback from headerless binary audio data.