Free online ALAC to AAC converter

Some car stereos, editors, mobile devices, and sharing workflows accept AAC but reject ALAC or do not handle it reliably. Converting the lossless source to AAC reduces file size and produces a format supported by most portable and playback software.

What the ALAC format is

ALAC means Apple Lossless Audio Codec. It compresses audio without discarding data, so decoding it reproduces the original PCM samples exactly. ALAC is a codec rather than a container and is usually stored in an MPEG-4 audio container with the .m4a extension; the extension alone does not prove that a file contains ALAC. Apple Music, iTunes, Apple devices, CD-ripping software, and lossless music libraries commonly use it. ALAC can contain CD-quality or higher-resolution audio.

What the AAC format is

AAC means Advanced Audio Coding. It is a lossy codec that produces much smaller files than ALAC, WAV, or FLAC at similar perceived listening quality. AAC is supported by modern phones, browsers, media players, streaming systems, car stereos, and video-editing applications. AAC audio is normally stored in an MPEG-4 container as .m4a; an elementary AAC stream uses .aac, usually with ADTS framing.

How to convert the files

Using 101convert

1. Open the ALAC-to-AAC converter on 101convert.com.
2. Upload the source file, normally an ALAC-encoded .m4a.
3. Choose AAC and select a bitrate such as 256 kbps, if the converter provides that setting.
4. Start the conversion and download the resulting .m4a or .aac file.

The conversion runs without installed software and is free on 101convert.com. Do not upload audio that must remain private, and test the downloaded file before deleting the original.

Using FFmpeg locally

FFmpeg is available for Windows, macOS, and Linux. This command creates AAC-LC audio in an M4A container:

ffmpeg -i "input.m4a" -map 0:a:0 -map_metadata 0 -c:a aac -b:a 256k "output.m4a"

Replace the filenames with the actual paths. The command copies available stream metadata but may not preserve embedded artwork in every source; check tags and cover art afterward. To create an elementary AAC stream for hardware or software that explicitly requires it, use an .aac destination instead: ffmpeg -i "input.m4a" -c:a aac -b:a 256k "output.aac". M4A generally provides better tagging and application compatibility.

Using Apple Music or iTunes

1. In macOS Music, open Music → Settings → Files → Import Settings. In iTunes for Windows, open Edit → Preferences → General → Import Settings.
2. Set the encoder to AAC Encoder and select the required bitrate or quality setting.
3. Import the ALAC track if it is not already in the library.
4. Select the track and choose File → Convert → Create AAC Version.

The application creates an AAC copy beside the ALAC original; it does not replace the source.

Quality and compatibility limits

AAC is lossy, so the conversion permanently removes information. Converting the AAC result back to ALAC cannot restore the discarded data. A 192–256 kbps AAC file is suitable for most listening; use a lower bitrate to reduce size or a higher setting when prioritizing transparency, with diminishing audible gains at higher rates.

Keep the ALAC original for archival storage, future lossless editing, or later transcoding. Use .m4a unless a specification specifically demands a raw .aac stream. Verify the output in the intended player because support for AAC profiles, bitrates, metadata, and artwork varies among older devices.